diff --git a/src/js/array.js b/src/js/array.js
index f9cf161..0a5e283 100644
--- a/src/js/array.js
+++ b/src/js/array.js
@@ -12,7 +12,6 @@
 // Imports
 
 var AddIndexedProperty;
-var FLAG_harmony_tolength;
 var FLAG_harmony_species;
 var GetIterator;
 var GetMethod;
@@ -28,7 +27,6 @@
 var ObserveBeginPerformSplice;
 var ObserveEndPerformSplice;
 var ObserveEnqueueSpliceRecord;
-var SameValueZero;
 var iteratorSymbol = utils.ImportNow("iterator_symbol");
 var unscopablesSymbol = utils.ImportNow("unscopables_symbol");
 
@@ -44,11 +42,9 @@
   ObserveBeginPerformSplice = from.ObserveBeginPerformSplice;
   ObserveEndPerformSplice = from.ObserveEndPerformSplice;
   ObserveEnqueueSpliceRecord = from.ObserveEnqueueSpliceRecord;
-  SameValueZero = from.SameValueZero;
 });
 
 utils.ImportFromExperimental(function(from) {
-  FLAG_harmony_tolength = from.FLAG_harmony_tolength;
   FLAG_harmony_species = from.FLAG_harmony_species;
 });
 
@@ -213,8 +209,6 @@
         elements[elements_length++] = e;
       }
       elements.length = elements_length;
-      var result = %_FastOneByteArrayJoin(elements, '');
-      if (!IS_UNDEFINED(result)) return result;
       return %StringBuilderConcat(elements, elements_length, '');
     }
     // Non-empty separator case.
@@ -237,9 +231,6 @@
         elements[i] = e;
       }
     }
-    var result = %_FastOneByteArrayJoin(elements, separator);
-    if (!IS_UNDEFINED(result)) return result;
-
     return %StringBuilderJoin(elements, length, separator);
   } finally {
     // Make sure to remove the last element of the visited array no
@@ -431,7 +422,7 @@
 
 
 function InnerArrayToLocaleString(array, length) {
-  var len = TO_LENGTH_OR_UINT32(length);
+  var len = TO_LENGTH(length);
   if (len === 0) return "";
   return Join(array, len, ',', ConvertToLocaleString);
 }
@@ -451,9 +442,6 @@
     separator = TO_STRING(separator);
   }
 
-  var result = %_FastOneByteArrayJoin(array, separator);
-  if (!IS_UNDEFINED(result)) return result;
-
   // Fast case for one-element arrays.
   if (length === 1) {
     var e = array[0];
@@ -469,7 +457,7 @@
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.join");
 
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
 
   return InnerArrayJoin(separator, array, length);
 }
@@ -498,7 +486,7 @@
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.pop");
 
   var array = TO_OBJECT(this);
-  var n = TO_LENGTH_OR_UINT32(array.length);
+  var n = TO_LENGTH(array.length);
   if (n == 0) {
     array.length = n;
     return;
@@ -516,13 +504,13 @@
 
 
 function ObservedArrayPush() {
-  var n = TO_LENGTH_OR_UINT32(this.length);
-  var m = %_ArgumentsLength();
+  var n = TO_LENGTH(this.length);
+  var m = arguments.length;
 
   try {
     ObserveBeginPerformSplice(this);
     for (var i = 0; i < m; i++) {
-      this[i+n] = %_Arguments(i);
+      this[i+n] = arguments[i];
     }
     var new_length = n + m;
     this.length = new_length;
@@ -544,8 +532,8 @@
     return ObservedArrayPush.apply(this, arguments);
 
   var array = TO_OBJECT(this);
-  var n = TO_LENGTH_OR_UINT32(array.length);
-  var m = %_ArgumentsLength();
+  var n = TO_LENGTH(array.length);
+  var m = arguments.length;
 
   // It appears that there is no enforced, absolute limit on the number of
   // arguments, but it would surely blow the stack to use 2**30 or more.
@@ -557,7 +545,7 @@
   }
 
   for (var i = 0; i < m; i++) {
-    array[i+n] = %_Arguments(i);
+    array[i+n] = arguments[i];
   }
 
   var new_length = n + m;
@@ -650,7 +638,7 @@
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.reverse");
 
   var array = TO_OBJECT(this);
-  var len = TO_LENGTH_OR_UINT32(array.length);
+  var len = TO_LENGTH(array.length);
   var isArray = IS_ARRAY(array);
 
   if (UseSparseVariant(array, len, isArray, len)) {
@@ -685,7 +673,7 @@
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.shift");
 
   var array = TO_OBJECT(this);
-  var len = TO_LENGTH_OR_UINT32(array.length);
+  var len = TO_LENGTH(array.length);
 
   if (len === 0) {
     array.length = 0;
@@ -712,14 +700,14 @@
 
 
 function ObservedArrayUnshift() {
-  var len = TO_LENGTH_OR_UINT32(this.length);
-  var num_arguments = %_ArgumentsLength();
+  var len = TO_LENGTH(this.length);
+  var num_arguments = arguments.length;
 
   try {
     ObserveBeginPerformSplice(this);
     SimpleMove(this, 0, 0, len, num_arguments);
     for (var i = 0; i < num_arguments; i++) {
-      this[i] = %_Arguments(i);
+      this[i] = arguments[i];
     }
     var new_length = len + num_arguments;
     this.length = new_length;
@@ -739,8 +727,8 @@
     return ObservedArrayUnshift.apply(this, arguments);
 
   var array = TO_OBJECT(this);
-  var len = TO_LENGTH_OR_UINT32(array.length);
-  var num_arguments = %_ArgumentsLength();
+  var len = TO_LENGTH(array.length);
+  var num_arguments = arguments.length;
 
   if (len > 0 && UseSparseVariant(array, len, IS_ARRAY(array), len) &&
       !%object_is_sealed(array)) {
@@ -750,7 +738,7 @@
   }
 
   for (var i = 0; i < num_arguments; i++) {
-    array[i] = %_Arguments(i);
+    array[i] = arguments[i];
   }
 
   var new_length = len + num_arguments;
@@ -763,7 +751,7 @@
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.slice");
 
   var array = TO_OBJECT(this);
-  var len = TO_LENGTH_OR_UINT32(array.length);
+  var len = TO_LENGTH(array.length);
   var start_i = TO_INTEGER(start);
   var end_i = len;
 
@@ -833,8 +821,8 @@
 
 
 function ObservedArraySplice(start, delete_count) {
-  var num_arguments = %_ArgumentsLength();
-  var len = TO_LENGTH_OR_UINT32(this.length);
+  var num_arguments = arguments.length;
+  var len = TO_LENGTH(this.length);
   var start_i = ComputeSpliceStartIndex(TO_INTEGER(start), len);
   var del_count = ComputeSpliceDeleteCount(delete_count, num_arguments, len,
                                            start_i);
@@ -852,9 +840,9 @@
     // place of the deleted elements.
     var i = start_i;
     var arguments_index = 2;
-    var arguments_length = %_ArgumentsLength();
+    var arguments_length = arguments.length;
     while (arguments_index < arguments_length) {
-      this[i++] = %_Arguments(arguments_index++);
+      this[i++] = arguments[arguments_index++];
     }
     this.length = len - del_count + num_elements_to_add;
 
@@ -879,9 +867,9 @@
   if (%IsObserved(this))
     return ObservedArraySplice.apply(this, arguments);
 
-  var num_arguments = %_ArgumentsLength();
+  var num_arguments = arguments.length;
   var array = TO_OBJECT(this);
-  var len = TO_LENGTH_OR_UINT32(array.length);
+  var len = TO_LENGTH(array.length);
   var start_i = ComputeSpliceStartIndex(TO_INTEGER(start), len);
   var del_count = ComputeSpliceDeleteCount(delete_count, num_arguments, len,
                                            start_i);
@@ -915,9 +903,9 @@
   // place of the deleted elements.
   var i = start_i;
   var arguments_index = 2;
-  var arguments_length = %_ArgumentsLength();
+  var arguments_length = arguments.length;
   while (arguments_index < arguments_length) {
-    array[i++] = %_Arguments(arguments_index++);
+    array[i++] = arguments[arguments_index++];
   }
   array.length = len - del_count + num_elements_to_add;
 
@@ -1068,7 +1056,7 @@
   var CopyFromPrototype = function CopyFromPrototype(obj, length) {
     var max = 0;
     for (var proto = %_GetPrototype(obj); proto; proto = %_GetPrototype(proto)) {
-      var indices = %GetArrayKeys(proto, length);
+      var indices = IS_PROXY(proto) ? length : %GetArrayKeys(proto, length);
       if (IS_NUMBER(indices)) {
         // It's an interval.
         var proto_length = indices;
@@ -1097,7 +1085,7 @@
   // elements in that range.
   var ShadowPrototypeElements = function(obj, from, to) {
     for (var proto = %_GetPrototype(obj); proto; proto = %_GetPrototype(proto)) {
-      var indices = %GetArrayKeys(proto, to);
+      var indices = IS_PROXY(proto) ? to : %GetArrayKeys(proto, to);
       if (IS_NUMBER(indices)) {
         // It's an interval.
         var proto_length = indices;
@@ -1217,7 +1205,7 @@
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.sort");
 
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   return InnerArraySort(array, length, comparefn);
 }
 
@@ -1248,7 +1236,7 @@
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   if (!IS_CALLABLE(f)) throw MakeTypeError(kCalledNonCallable, f);
   var result = ArraySpeciesCreate(array, 0);
   return InnerArrayFilter(f, receiver, array, length, result);
@@ -1274,7 +1262,7 @@
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   InnerArrayForEach(f, receiver, array, length);
 }
 
@@ -1301,7 +1289,7 @@
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   return InnerArraySome(f, receiver, array, length);
 }
 
@@ -1325,7 +1313,7 @@
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   return InnerArrayEvery(f, receiver, array, length);
 }
 
@@ -1336,7 +1324,7 @@
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   if (!IS_CALLABLE(f)) throw MakeTypeError(kCalledNonCallable, f);
   var result = ArraySpeciesCreate(array, length);
   var is_array = IS_ARRAY(array);
@@ -1411,7 +1399,7 @@
 function ArrayIndexOf(element, index) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.indexOf");
 
-  var length = TO_LENGTH_OR_UINT32(this.length);
+  var length = TO_LENGTH(this.length);
   return InnerArrayIndexOf(this, element, index, length);
 }
 
@@ -1469,9 +1457,9 @@
 function ArrayLastIndexOf(element, index) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.lastIndexOf");
 
-  var length = TO_LENGTH_OR_UINT32(this.length);
+  var length = TO_LENGTH(this.length);
   return InnerArrayLastIndexOf(this, element, index, length,
-                        %_ArgumentsLength());
+                               arguments.length);
 }
 
 
@@ -1508,9 +1496,9 @@
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   return InnerArrayReduce(callback, current, array, length,
-                          %_ArgumentsLength());
+                          arguments.length);
 }
 
 
@@ -1548,9 +1536,9 @@
   // Pull out the length so that side effects are visible before the
   // callback function is checked.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   return InnerArrayReduceRight(callback, current, array, length,
-                               %_ArgumentsLength());
+                               arguments.length);
 }
 
 
@@ -1701,7 +1689,7 @@
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.fill");
 
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
 
   return InnerArrayFill(value, start, end, array, length);
 }
@@ -1726,7 +1714,7 @@
 
   while (k < length) {
     var elementK = array[k];
-    if (SameValueZero(searchElement, elementK)) {
+    if (%SameValueZero(searchElement, elementK)) {
       return true;
     }
 
@@ -1778,23 +1766,10 @@
 
   if (!IS_UNDEFINED(iterable)) {
     result = %IsConstructor(this) ? new this() : [];
-
-    var iterator = GetIterator(items, iterable);
-
     k = 0;
-    while (true) {
-      var next = iterator.next();
 
-      if (!IS_RECEIVER(next)) {
-        throw MakeTypeError(kIteratorResultNotAnObject, next);
-      }
-
-      if (next.done) {
-        result.length = k;
-        return result;
-      }
-
-      nextValue = next.value;
+    for (nextValue of
+         { [iteratorSymbol]() { return GetIterator(items, iterable) } }) {
       if (mapping) {
         mappedValue = %_Call(mapfn, receiver, nextValue, k);
       } else {
@@ -1803,6 +1778,8 @@
       AddArrayElement(this, result, k, mappedValue);
       k++;
     }
+    result.length = k;
+    return result;
   } else {
     var len = TO_LENGTH(items.length);
     result = %IsConstructor(this) ? new this(len) : new GlobalArray(len);
@@ -1824,13 +1801,13 @@
 
 
 // ES6, draft 05-22-14, section 22.1.2.3
-function ArrayOf() {
-  var length = %_ArgumentsLength();
+function ArrayOf(...args) {
+  var length = args.length;
   var constructor = this;
   // TODO: Implement IsConstructor (ES6 section 7.2.5)
   var array = %IsConstructor(constructor) ? new constructor(length) : [];
   for (var i = 0; i < length; i++) {
-    AddArrayElement(constructor, array, i, %_Arguments(i));
+    AddArrayElement(constructor, array, i, args[i]);
   }
   array.length = length;
   return array;
diff --git a/src/js/generator.js b/src/js/generator.js
index 7f43656..3dcdcc0 100644
--- a/src/js/generator.js
+++ b/src/js/generator.js
@@ -36,15 +36,31 @@
   if (continuation > 0) {
     // Generator is suspended.
     DEBUG_PREPARE_STEP_IN_IF_STEPPING(this);
-    try {
-      return %_GeneratorNext(this, value);
-    } catch (e) {
-      %GeneratorClose(this);
-      throw e;
-    }
+    return %_GeneratorNext(this, value);
   } else if (continuation == 0) {
     // Generator is already closed.
-    return { value: void 0, done: true };
+    return %_CreateIterResultObject(UNDEFINED, true);
+  } else {
+    // Generator is running.
+    throw MakeTypeError(kGeneratorRunning);
+  }
+}
+
+
+function GeneratorObjectReturn(value) {
+  if (!IS_GENERATOR(this)) {
+    throw MakeTypeError(kIncompatibleMethodReceiver,
+                        '[Generator].prototype.return', this);
+  }
+
+  var continuation = %GeneratorGetContinuation(this);
+  if (continuation > 0) {
+    // Generator is suspended.
+    DEBUG_PREPARE_STEP_IN_IF_STEPPING(this);
+    return %_GeneratorReturn(this, value);
+  } else if (continuation == 0) {
+    // Generator is already closed.
+    return %_CreateIterResultObject(value, true);
   } else {
     // Generator is running.
     throw MakeTypeError(kGeneratorRunning);
@@ -61,12 +77,8 @@
   var continuation = %GeneratorGetContinuation(this);
   if (continuation > 0) {
     // Generator is suspended.
-    try {
-      return %_GeneratorThrow(this, exn);
-    } catch (e) {
-      %GeneratorClose(this);
-      throw e;
-    }
+    DEBUG_PREPARE_STEP_IN_IF_STEPPING(this);
+    return %_GeneratorThrow(this, exn);
   } else if (continuation == 0) {
     // Generator is already closed.
     throw exn;
@@ -78,9 +90,11 @@
 
 // ----------------------------------------------------------------------------
 
-// Both Runtime_GeneratorNext and Runtime_GeneratorThrow are supported by
-// neither Crankshaft nor TurboFan, disable optimization of wrappers here.
+// None of the three resume operations (Runtime_GeneratorNext,
+// Runtime_GeneratorReturn, Runtime_GeneratorThrow) is supported by
+// Crankshaft or TurboFan.  Disable optimization of wrappers here.
 %NeverOptimizeFunction(GeneratorObjectNext);
+%NeverOptimizeFunction(GeneratorObjectReturn);
 %NeverOptimizeFunction(GeneratorObjectThrow);
 
 // Set up non-enumerable functions on the generator prototype object.
@@ -88,6 +102,7 @@
 utils.InstallFunctions(GeneratorObjectPrototype,
                        DONT_ENUM,
                       ["next", GeneratorObjectNext,
+                       "return", GeneratorObjectReturn,
                        "throw", GeneratorObjectThrow]);
 
 %AddNamedProperty(GeneratorObjectPrototype, "constructor",
diff --git a/src/js/harmony-reflect.js b/src/js/harmony-reflect.js
deleted file mode 100644
index dcadad5..0000000
--- a/src/js/harmony-reflect.js
+++ /dev/null
@@ -1,37 +0,0 @@
-// Copyright 2013-2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-(function(global, utils) {
-
-'use strict';
-
-%CheckIsBootstrapping();
-
-// -------------------------------------------------------------------
-// Imports
-
-var GlobalReflect = global.Reflect;
-var MakeTypeError;
-var ReflectApply = utils.ImportNow("reflect_apply");
-var ReflectConstruct = utils.ImportNow("reflect_construct");
-
-utils.Import(function(from) {
-  MakeTypeError = from.MakeTypeError;
-});
-
-// -------------------------------------------------------------------
-
-function ReflectEnumerate(obj) {
-  if (!IS_RECEIVER(obj))
-    throw MakeTypeError(kCalledOnNonObject, "Reflect.enumerate")
-  return (function* () { for (var x in obj) yield x })();
-}
-
-utils.InstallFunctions(GlobalReflect, DONT_ENUM, [
-  "apply", ReflectApply,
-  "construct", ReflectConstruct,
-  "enumerate", ReflectEnumerate
-]);
-
-})
diff --git a/src/js/i18n.js b/src/js/i18n.js
index 7e00fcd..7b2f5a1 100644
--- a/src/js/i18n.js
+++ b/src/js/i18n.js
@@ -232,8 +232,8 @@
           // DateTimeFormat.format needs to be 0 arg method, but can stil
           // receive optional dateValue param. If one was provided, pass it
           // along.
-          if (%_ArgumentsLength() > 0) {
-            return implementation(that, %_Arguments(0));
+          if (arguments.length > 0) {
+            return implementation(that, arguments[0]);
           } else {
             return implementation(that);
           }
@@ -1002,8 +1002,8 @@
  * @constructor
  */
 %AddNamedProperty(Intl, 'Collator', function() {
-    var locales = %_Arguments(0);
-    var options = %_Arguments(1);
+    var locales = arguments[0];
+    var options = arguments[1];
 
     if (!this || this === Intl) {
       // Constructor is called as a function.
@@ -1060,7 +1060,7 @@
       throw MakeTypeError(kOrdinaryFunctionCalledAsConstructor);
     }
 
-    return supportedLocalesOf('collator', locales, %_Arguments(1));
+    return supportedLocalesOf('collator', locales, arguments[1]);
   },
   DONT_ENUM
 );
@@ -1255,8 +1255,8 @@
  * @constructor
  */
 %AddNamedProperty(Intl, 'NumberFormat', function() {
-    var locales = %_Arguments(0);
-    var options = %_Arguments(1);
+    var locales = arguments[0];
+    var options = arguments[1];
 
     if (!this || this === Intl) {
       // Constructor is called as a function.
@@ -1332,7 +1332,7 @@
       throw MakeTypeError(kOrdinaryFunctionCalledAsConstructor);
     }
 
-    return supportedLocalesOf('numberformat', locales, %_Arguments(1));
+    return supportedLocalesOf('numberformat', locales, arguments[1]);
   },
   DONT_ENUM
 );
@@ -1659,8 +1659,8 @@
  * @constructor
  */
 %AddNamedProperty(Intl, 'DateTimeFormat', function() {
-    var locales = %_Arguments(0);
-    var options = %_Arguments(1);
+    var locales = arguments[0];
+    var options = arguments[1];
 
     if (!this || this === Intl) {
       // Constructor is called as a function.
@@ -1755,7 +1755,7 @@
       throw MakeTypeError(kOrdinaryFunctionCalledAsConstructor);
     }
 
-    return supportedLocalesOf('dateformat', locales, %_Arguments(1));
+    return supportedLocalesOf('dateformat', locales, arguments[1]);
   },
   DONT_ENUM
 );
@@ -1886,8 +1886,8 @@
  * @constructor
  */
 %AddNamedProperty(Intl, 'v8BreakIterator', function() {
-    var locales = %_Arguments(0);
-    var options = %_Arguments(1);
+    var locales = arguments[0];
+    var options = arguments[1];
 
     if (!this || this === Intl) {
       // Constructor is called as a function.
@@ -1943,7 +1943,7 @@
       throw MakeTypeError(kOrdinaryFunctionCalledAsConstructor);
     }
 
-    return supportedLocalesOf('breakiterator', locales, %_Arguments(1));
+    return supportedLocalesOf('breakiterator', locales, arguments[1]);
   },
   DONT_ENUM
 );
@@ -2061,8 +2061,8 @@
       throw MakeTypeError(kMethodInvokedOnNullOrUndefined);
     }
 
-    var locales = %_Arguments(1);
-    var options = %_Arguments(2);
+    var locales = arguments[1];
+    var options = arguments[2];
     var collator = cachedOrNewService('collator', locales, options);
     return compare(collator, this, that);
   }
@@ -2085,7 +2085,7 @@
     CHECK_OBJECT_COERCIBLE(this, "String.prototype.normalize");
     var s = TO_STRING(this);
 
-    var formArg = %_Arguments(0);
+    var formArg = arguments[0];
     var form = IS_UNDEFINED(formArg) ? 'NFC' : TO_STRING(formArg);
 
     var NORMALIZATION_FORMS = ['NFC', 'NFD', 'NFKC', 'NFKD'];
@@ -2114,8 +2114,8 @@
       throw MakeTypeError(kMethodInvokedOnWrongType, "Number");
     }
 
-    var locales = %_Arguments(0);
-    var options = %_Arguments(1);
+    var locales = arguments[0];
+    var options = arguments[1];
     var numberFormat = cachedOrNewService('numberformat', locales, options);
     return formatNumber(numberFormat, this);
   }
@@ -2151,8 +2151,8 @@
       throw MakeTypeError(kOrdinaryFunctionCalledAsConstructor);
     }
 
-    var locales = %_Arguments(0);
-    var options = %_Arguments(1);
+    var locales = arguments[0];
+    var options = arguments[1];
     return toLocaleDateTime(
         this, locales, options, 'any', 'all', 'dateformatall');
   }
@@ -2169,8 +2169,8 @@
       throw MakeTypeError(kOrdinaryFunctionCalledAsConstructor);
     }
 
-    var locales = %_Arguments(0);
-    var options = %_Arguments(1);
+    var locales = arguments[0];
+    var options = arguments[1];
     return toLocaleDateTime(
         this, locales, options, 'date', 'date', 'dateformatdate');
   }
@@ -2187,8 +2187,8 @@
       throw MakeTypeError(kOrdinaryFunctionCalledAsConstructor);
     }
 
-    var locales = %_Arguments(0);
-    var options = %_Arguments(1);
+    var locales = arguments[0];
+    var options = arguments[1];
     return toLocaleDateTime(
         this, locales, options, 'time', 'time', 'dateformattime');
   }
diff --git a/src/js/json.js b/src/js/json.js
index b8836ea..73d7802 100644
--- a/src/js/json.js
+++ b/src/js/json.js
@@ -187,7 +187,7 @@
 
 
 function JSONStringify(value, replacer, space) {
-  if (%_ArgumentsLength() == 1 && !IS_PROXY(value)) {
+  if (arguments.length === 1 && !IS_PROXY(value)) {
     return %BasicJSONStringify(value);
   }
   if (!IS_CALLABLE(replacer) && %is_arraylike(replacer)) {
@@ -234,6 +234,9 @@
   } else {
     gap = "";
   }
+  if (!IS_CALLABLE(replacer) && !property_list && !gap && !IS_PROXY(value)) {
+    return %BasicJSONStringify(value);
+  }
   return JSONSerialize('', {'': value}, replacer, new InternalArray(), "", gap);
 }
 
diff --git a/src/js/macros.py b/src/js/macros.py
index 3bcc8c1..b2a7856 100644
--- a/src/js/macros.py
+++ b/src/js/macros.py
@@ -67,9 +67,9 @@
 macro IS_BOOLEAN(arg)           = (typeof(arg) === 'boolean');
 macro IS_BOOLEAN_WRAPPER(arg)   = (%_ClassOf(arg) === 'Boolean');
 macro IS_DATAVIEW(arg)          = (%_ClassOf(arg) === 'DataView');
-macro IS_DATE(arg)              = (%_IsDate(arg));
+macro IS_DATE(arg)              = (%IsDate(arg));
 macro IS_ERROR(arg)             = (%_ClassOf(arg) === 'Error');
-macro IS_FUNCTION(arg)          = (%_IsFunction(arg));
+macro IS_FUNCTION(arg)          = (%IsFunction(arg));
 macro IS_GENERATOR(arg)         = (%_ClassOf(arg) === 'Generator');
 macro IS_GLOBAL(arg)            = (%_ClassOf(arg) === 'global');
 macro IS_MAP(arg)               = (%_ClassOf(arg) === 'Map');
@@ -85,7 +85,7 @@
 macro IS_SET(arg)               = (%_ClassOf(arg) === 'Set');
 macro IS_SET_ITERATOR(arg)      = (%_ClassOf(arg) === 'Set Iterator');
 macro IS_SHAREDARRAYBUFFER(arg) = (%_ClassOf(arg) === 'SharedArrayBuffer');
-macro IS_SIMD_VALUE(arg)        = (%_IsSimdValue(arg));
+macro IS_SIMD_VALUE(arg)        = (%IsSimdValue(arg));
 macro IS_STRING(arg)            = (typeof(arg) === 'string');
 macro IS_STRING_WRAPPER(arg)    = (%_ClassOf(arg) === 'String');
 macro IS_STRONG(arg)            = (%IsStrong(arg));
@@ -114,8 +114,6 @@
 macro TO_INT32(arg) = ((arg) | 0);
 macro TO_UINT32(arg) = ((arg) >>> 0);
 macro TO_LENGTH(arg) = (%_ToLength(arg));
-macro TO_LENGTH_OR_UINT32(arg) = (FLAG_harmony_tolength ? TO_LENGTH(arg) : TO_UINT32(arg));
-macro TO_LENGTH_OR_INTEGER(arg) = (FLAG_harmony_tolength ? TO_LENGTH(arg) : TO_INTEGER(arg));
 macro TO_STRING(arg) = (%_ToString(arg));
 macro TO_NUMBER(arg) = (%_ToNumber(arg));
 macro TO_OBJECT(arg) = (%_ToObject(arg));
diff --git a/src/js/math.js b/src/js/math.js
index 990a7e9..a698fd4 100644
--- a/src/js/math.js
+++ b/src/js/math.js
@@ -75,60 +75,6 @@
   return %_MathLogRT(TO_NUMBER(x));
 }
 
-// ECMA 262 - 15.8.2.11
-function MathMax(arg1, arg2) {  // length == 2
-  var length = %_ArgumentsLength();
-  if (length == 2) {
-    arg1 = TO_NUMBER(arg1);
-    arg2 = TO_NUMBER(arg2);
-    if (arg2 > arg1) return arg2;
-    if (arg1 > arg2) return arg1;
-    if (arg1 == arg2) {
-      // Make sure -0 is considered less than +0.
-      return (arg1 === 0 && %_IsMinusZero(arg1)) ? arg2 : arg1;
-    }
-    // All comparisons failed, one of the arguments must be NaN.
-    return NaN;
-  }
-  var r = -INFINITY;
-  for (var i = 0; i < length; i++) {
-    var n = %_Arguments(i);
-    n = TO_NUMBER(n);
-    // Make sure +0 is considered greater than -0.
-    if (NUMBER_IS_NAN(n) || n > r || (r === 0 && n === 0 && %_IsMinusZero(r))) {
-      r = n;
-    }
-  }
-  return r;
-}
-
-// ECMA 262 - 15.8.2.12
-function MathMin(arg1, arg2) {  // length == 2
-  var length = %_ArgumentsLength();
-  if (length == 2) {
-    arg1 = TO_NUMBER(arg1);
-    arg2 = TO_NUMBER(arg2);
-    if (arg2 > arg1) return arg1;
-    if (arg1 > arg2) return arg2;
-    if (arg1 == arg2) {
-      // Make sure -0 is considered less than +0.
-      return (arg1 === 0 && %_IsMinusZero(arg1)) ? arg1 : arg2;
-    }
-    // All comparisons failed, one of the arguments must be NaN.
-    return NaN;
-  }
-  var r = INFINITY;
-  for (var i = 0; i < length; i++) {
-    var n = %_Arguments(i);
-    n = TO_NUMBER(n);
-    // Make sure -0 is considered less than +0.
-    if (NUMBER_IS_NAN(n) || n < r || (r === 0 && n === 0 && %_IsMinusZero(n))) {
-      r = n;
-    }
-  }
-  return r;
-}
-
 // ECMA 262 - 15.8.2.13
 function MathPowJS(x, y) {
   return %_MathPow(TO_NUMBER(x), TO_NUMBER(y));
@@ -218,17 +164,14 @@
   // We may want to introduce fast paths for two arguments and when
   // normalization to avoid overflow is not necessary.  For now, we
   // simply assume the general case.
-  var length = %_ArgumentsLength();
-  var args = new InternalArray(length);
+  var length = arguments.length;
   var max = 0;
   for (var i = 0; i < length; i++) {
-    var n = %_Arguments(i);
-    n = TO_NUMBER(n);
-    if (n === INFINITY || n === -INFINITY) return INFINITY;
-    n = MathAbs(n);
+    var n = MathAbs(arguments[i]);
     if (n > max) max = n;
-    args[i] = n;
+    arguments[i] = n;
   }
+  if (max === INFINITY) return INFINITY;
 
   // Kahan summation to avoid rounding errors.
   // Normalize the numbers to the largest one to avoid overflow.
@@ -236,7 +179,7 @@
   var sum = 0;
   var compensation = 0;
   for (var i = 0; i < length; i++) {
-    var n = args[i] / max;
+    var n = arguments[i] / max;
     var summand = n * n - compensation;
     var preliminary = sum + summand;
     compensation = (preliminary - sum) - summand;
@@ -314,8 +257,6 @@
   "sqrt", MathSqrtJS,
   "atan2", MathAtan2JS,
   "pow", MathPowJS,
-  "max", MathMax,
-  "min", MathMin,
   "imul", MathImul,
   "sign", MathSign,
   "trunc", MathTrunc,
@@ -349,8 +290,6 @@
   to.MathExp = MathExp;
   to.MathFloor = MathFloorJS;
   to.IntRandom = MathRandomRaw;
-  to.MathMax = MathMax;
-  to.MathMin = MathMin;
 });
 
 })
diff --git a/src/js/prologue.js b/src/js/prologue.js
index 2779393..24225a0 100644
--- a/src/js/prologue.js
+++ b/src/js/prologue.js
@@ -179,8 +179,6 @@
     "MapEntries",
     "MapIterator",
     "MapIteratorNext",
-    "MathMax",
-    "MathMin",
     "MaxSimple",
     "MinSimple",
     "ObjectDefineProperty",
@@ -189,7 +187,6 @@
     "PromiseChain",
     "PromiseDeferred",
     "PromiseResolved",
-    "SameValueZero",
     "SetIterator",
     "SetIteratorNext",
     "SetValues",
diff --git a/src/js/proxy.js b/src/js/proxy.js
index 842bac0..a111c09 100644
--- a/src/js/proxy.js
+++ b/src/js/proxy.js
@@ -12,11 +12,6 @@
 // Imports
 //
 var GlobalProxy = global.Proxy;
-var MakeTypeError;
-
-utils.Import(function(from) {
-  MakeTypeError = from.MakeTypeError;
-});
 
 //----------------------------------------------------------------------------
 
@@ -25,33 +20,6 @@
   return {proxy: p, revoke: () => %JSProxyRevoke(p)};
 }
 
-// -------------------------------------------------------------------
-// Proxy Builtins
-
-// Implements part of ES6 9.5.11 Proxy.[[Enumerate]]:
-// Call the trap, which should return an iterator, exhaust the iterator,
-// and return an array containing the values.
-function ProxyEnumerate(trap, handler, target) {
-  // 7. Let trapResult be ? Call(trap, handler, «target»).
-  var trap_result = %_Call(trap, handler, target);
-  // 8. If Type(trapResult) is not Object, throw a TypeError exception.
-  if (!IS_RECEIVER(trap_result)) {
-    throw MakeTypeError(kProxyEnumerateNonObject);
-  }
-  // 9. Return trapResult.
-  var result = [];
-  for (var it = trap_result.next(); !it.done; it = trap_result.next()) {
-    var key = it.value;
-    // Not yet spec'ed as of 2015-11-25, but will be spec'ed soon:
-    // If the iterator returns a non-string value, throw a TypeError.
-    if (!IS_STRING(key)) {
-      throw MakeTypeError(kProxyEnumerateNonString);
-    }
-    result.push(key);
-  }
-  return result;
-}
-
 //-------------------------------------------------------------------
 
 //Set up non-enumerable properties of the Proxy object.
@@ -59,11 +27,4 @@
   "revocable", ProxyCreateRevocable
 ]);
 
-// -------------------------------------------------------------------
-// Exports
-
-%InstallToContext([
-  "proxy_enumerate", ProxyEnumerate,
-]);
-
 })
diff --git a/src/js/regexp.js b/src/js/regexp.js
index eeacd6e..e80d019 100644
--- a/src/js/regexp.js
+++ b/src/js/regexp.js
@@ -9,7 +9,7 @@
 // -------------------------------------------------------------------
 // Imports
 
-var FLAG_harmony_tolength;
+var ExpandReplacement;
 var GlobalObject = global.Object;
 var GlobalRegExp = global.RegExp;
 var GlobalRegExpPrototype;
@@ -17,14 +17,12 @@
 var InternalPackedArray = utils.InternalPackedArray;
 var MakeTypeError;
 var matchSymbol = utils.ImportNow("match_symbol");
+var replaceSymbol = utils.ImportNow("replace_symbol");
 var searchSymbol = utils.ImportNow("search_symbol");
 var splitSymbol = utils.ImportNow("split_symbol");
 
-utils.ImportFromExperimental(function(from) {
-  FLAG_harmony_tolength = from.FLAG_harmony_tolength;
-});
-
 utils.Import(function(from) {
+  ExpandReplacement = from.ExpandReplacement;
   MakeTypeError = from.MakeTypeError;
 });
 
@@ -176,7 +174,7 @@
 
   // Conversion is required by the ES2015 specification (RegExpBuiltinExec
   // algorithm, step 4) even if the value is discarded for non-global RegExps.
-  var i = TO_LENGTH_OR_INTEGER(lastIndex);
+  var i = TO_LENGTH(lastIndex);
 
   var updateLastIndex = REGEXP_GLOBAL(this) || REGEXP_STICKY(this);
   if (updateLastIndex) {
@@ -223,7 +221,7 @@
 
   // Conversion is required by the ES2015 specification (RegExpBuiltinExec
   // algorithm, step 4) even if the value is discarded for non-global RegExps.
-  var i = TO_LENGTH_OR_INTEGER(lastIndex);
+  var i = TO_LENGTH(lastIndex);
 
   if (REGEXP_GLOBAL(this) || REGEXP_STICKY(this)) {
     if (i < 0 || i > string.length) {
@@ -262,7 +260,7 @@
 }
 
 function TrimRegExp(regexp) {
-  if (!%_ObjectEquals(regexp_key, regexp)) {
+  if (regexp_key !== regexp) {
     regexp_key = regexp;
     regexp_val =
       new GlobalRegExp(
@@ -283,8 +281,11 @@
       %IncrementUseCounter(kRegExpPrototypeToString);
       return '/(?:)/';
     }
-    throw MakeTypeError(kIncompatibleMethodReceiver,
-                        'RegExp.prototype.toString', this);
+    if (!IS_RECEIVER(this)) {
+      throw MakeTypeError(
+          kIncompatibleMethodReceiver, 'RegExp.prototype.toString', this);
+    }
+    return '/' + TO_STRING(this.source) + '/' + TO_STRING(this.flags);
   }
   var result = '/' + REGEXP_SOURCE(this) + '/';
   if (REGEXP_GLOBAL(this)) result += 'g';
@@ -296,6 +297,15 @@
 }
 
 
+function AtSurrogatePair(subject, index) {
+  if (index + 1 >= subject.length) return false;
+  var first = %_StringCharCodeAt(subject, index);
+  if (first < 0xD800 || first > 0xDBFF) return false;
+  var second = %_StringCharCodeAt(subject, index + 1);
+  return second >= 0xDC00 || second <= 0xDFFF;
+}
+
+
 // ES6 21.2.5.11.
 function RegExpSplit(string, limit) {
   // TODO(yangguo): allow non-regexp receivers.
@@ -337,7 +347,11 @@
 
     // We ignore a zero-length match at the currentIndex.
     if (startIndex === endIndex && endIndex === currentIndex) {
-      startIndex++;
+      if (REGEXP_UNICODE(this) && AtSurrogatePair(subject, startIndex)) {
+        startIndex += 2;
+      } else {
+        startIndex++;
+      }
       continue;
     }
 
@@ -382,6 +396,175 @@
 }
 
 
+// ES6 21.2.5.8.
+
+// TODO(lrn): This array will survive indefinitely if replace is never
+// called again. However, it will be empty, since the contents are cleared
+// in the finally block.
+var reusableReplaceArray = new InternalArray(4);
+
+// Helper function for replacing regular expressions with the result of a
+// function application in String.prototype.replace.
+function StringReplaceGlobalRegExpWithFunction(subject, regexp, replace) {
+  var resultArray = reusableReplaceArray;
+  if (resultArray) {
+    reusableReplaceArray = null;
+  } else {
+    // Inside a nested replace (replace called from the replacement function
+    // of another replace) or we have failed to set the reusable array
+    // back due to an exception in a replacement function. Create a new
+    // array to use in the future, or until the original is written back.
+    resultArray = new InternalArray(16);
+  }
+  var res = %RegExpExecMultiple(regexp,
+                                subject,
+                                RegExpLastMatchInfo,
+                                resultArray);
+  regexp.lastIndex = 0;
+  if (IS_NULL(res)) {
+    // No matches at all.
+    reusableReplaceArray = resultArray;
+    return subject;
+  }
+  var len = res.length;
+  if (NUMBER_OF_CAPTURES(RegExpLastMatchInfo) == 2) {
+    // If the number of captures is two then there are no explicit captures in
+    // the regexp, just the implicit capture that captures the whole match.  In
+    // this case we can simplify quite a bit and end up with something faster.
+    // The builder will consist of some integers that indicate slices of the
+    // input string and some replacements that were returned from the replace
+    // function.
+    var match_start = 0;
+    for (var i = 0; i < len; i++) {
+      var elem = res[i];
+      if (%_IsSmi(elem)) {
+        // Integers represent slices of the original string.
+        if (elem > 0) {
+          match_start = (elem >> 11) + (elem & 0x7ff);
+        } else {
+          match_start = res[++i] - elem;
+        }
+      } else {
+        var func_result = replace(elem, match_start, subject);
+        // Overwrite the i'th element in the results with the string we got
+        // back from the callback function.
+        res[i] = TO_STRING(func_result);
+        match_start += elem.length;
+      }
+    }
+  } else {
+    for (var i = 0; i < len; i++) {
+      var elem = res[i];
+      if (!%_IsSmi(elem)) {
+        // elem must be an Array.
+        // Use the apply argument as backing for global RegExp properties.
+        var func_result = %Apply(replace, UNDEFINED, elem, 0, elem.length);
+        // Overwrite the i'th element in the results with the string we got
+        // back from the callback function.
+        res[i] = TO_STRING(func_result);
+      }
+    }
+  }
+  var result = %StringBuilderConcat(res, len, subject);
+  resultArray.length = 0;
+  reusableReplaceArray = resultArray;
+  return result;
+}
+
+
+// Compute the string of a given regular expression capture.
+function CaptureString(string, lastCaptureInfo, index) {
+  // Scale the index.
+  var scaled = index << 1;
+  // Compute start and end.
+  var start = lastCaptureInfo[CAPTURE(scaled)];
+  // If start isn't valid, return undefined.
+  if (start < 0) return;
+  var end = lastCaptureInfo[CAPTURE(scaled + 1)];
+  return %_SubString(string, start, end);
+}
+
+
+function StringReplaceNonGlobalRegExpWithFunction(subject, regexp, replace) {
+  var matchInfo = DoRegExpExec(regexp, subject, 0);
+  if (IS_NULL(matchInfo)) {
+    regexp.lastIndex = 0;
+    return subject;
+  }
+  var index = matchInfo[CAPTURE0];
+  var result = %_SubString(subject, 0, index);
+  var endOfMatch = matchInfo[CAPTURE1];
+  // Compute the parameter list consisting of the match, captures, index,
+  // and subject for the replace function invocation.
+  // The number of captures plus one for the match.
+  var m = NUMBER_OF_CAPTURES(matchInfo) >> 1;
+  var replacement;
+  if (m == 1) {
+    // No captures, only the match, which is always valid.
+    var s = %_SubString(subject, index, endOfMatch);
+    // Don't call directly to avoid exposing the built-in global object.
+    replacement = replace(s, index, subject);
+  } else {
+    var parameters = new InternalArray(m + 2);
+    for (var j = 0; j < m; j++) {
+      parameters[j] = CaptureString(subject, matchInfo, j);
+    }
+    parameters[j] = index;
+    parameters[j + 1] = subject;
+
+    replacement = %Apply(replace, UNDEFINED, parameters, 0, j + 2);
+  }
+
+  result += replacement;  // The add method converts to string if necessary.
+  // Can't use matchInfo any more from here, since the function could
+  // overwrite it.
+  return result + %_SubString(subject, endOfMatch, subject.length);
+}
+
+
+function RegExpReplace(string, replace) {
+  // TODO(littledan): allow non-regexp receivers.
+  if (!IS_REGEXP(this)) {
+    throw MakeTypeError(kIncompatibleMethodReceiver,
+                        "RegExp.prototype.@@replace", this);
+  }
+  var subject = TO_STRING(string);
+  var search = this;
+
+  if (!IS_CALLABLE(replace)) {
+    replace = TO_STRING(replace);
+
+    if (!REGEXP_GLOBAL(search)) {
+      // Non-global regexp search, string replace.
+      var match = DoRegExpExec(search, subject, 0);
+      if (match == null) {
+        search.lastIndex = 0
+        return subject;
+      }
+      if (replace.length == 0) {
+        return %_SubString(subject, 0, match[CAPTURE0]) +
+               %_SubString(subject, match[CAPTURE1], subject.length)
+      }
+      return ExpandReplacement(replace, subject, RegExpLastMatchInfo,
+                                 %_SubString(subject, 0, match[CAPTURE0])) +
+             %_SubString(subject, match[CAPTURE1], subject.length);
+    }
+
+    // Global regexp search, string replace.
+    search.lastIndex = 0;
+    return %StringReplaceGlobalRegExpWithString(
+        subject, search, replace, RegExpLastMatchInfo);
+  }
+
+  if (REGEXP_GLOBAL(search)) {
+    // Global regexp search, function replace.
+    return StringReplaceGlobalRegExpWithFunction(subject, search, replace);
+  }
+  // Non-global regexp search, function replace.
+  return StringReplaceNonGlobalRegExpWithFunction(subject, search, replace);
+}
+
+
 // ES6 21.2.5.9.
 function RegExpSearch(string) {
   // TODO(yangguo): allow non-regexp receivers.
@@ -530,6 +713,7 @@
   "toString", RegExpToString,
   "compile", RegExpCompileJS,
   matchSymbol, RegExpMatch,
+  replaceSymbol, RegExpReplace,
   searchSymbol, RegExpSearch,
   splitSymbol, RegExpSplit,
 ]);
@@ -539,9 +723,6 @@
 utils.InstallGetter(GlobalRegExp.prototype, 'multiline', RegExpGetMultiline);
 utils.InstallGetter(GlobalRegExp.prototype, 'source', RegExpGetSource);
 
-// The length of compile is 1 in SpiderMonkey.
-%FunctionSetLength(GlobalRegExp.prototype.compile, 1);
-
 // The properties `input` and `$_` are aliases for each other.  When this
 // value is set the value it is set to is coerced to a string.
 // Getter and setter for the input.
diff --git a/src/js/runtime.js b/src/js/runtime.js
index 301d75a..7a61094 100644
--- a/src/js/runtime.js
+++ b/src/js/runtime.js
@@ -36,47 +36,12 @@
 
 // ----------------------------------------------------------------------------
 
-/* -----------------------------
-   - - -   H e l p e r s   - - -
-   -----------------------------
+
+/* ---------------------------------
+   - - -   U t i l i t i e s   - - -
+   ---------------------------------
 */
 
-function CONCAT_ITERABLE_TO_ARRAY(iterable) {
-  return %concat_iterable_to_array(this, iterable);
-};
-
-
-/* -------------------------------------
-   - - -   C o n v e r s i o n s   - - -
-   -------------------------------------
-*/
-
-// ES5, section 9.12
-function SameValue(x, y) {
-  if (typeof x != typeof y) return false;
-  if (IS_NUMBER(x)) {
-    if (NUMBER_IS_NAN(x) && NUMBER_IS_NAN(y)) return true;
-    // x is +0 and y is -0 or vice versa.
-    if (x === 0 && y === 0 && %_IsMinusZero(x) != %_IsMinusZero(y)) {
-      return false;
-    }
-  }
-  if (IS_SIMD_VALUE(x)) return %SimdSameValue(x, y);
-  return x === y;
-}
-
-
-// ES6, section 7.2.4
-function SameValueZero(x, y) {
-  if (typeof x != typeof y) return false;
-  if (IS_NUMBER(x)) {
-    if (NUMBER_IS_NAN(x) && NUMBER_IS_NAN(y)) return true;
-  }
-  if (IS_SIMD_VALUE(x)) return %SimdSameValueZero(x, y);
-  return x === y;
-}
-
-
 function ConcatIterableToArray(target, iterable) {
    var index = target.length;
    for (var element of iterable) {
@@ -86,12 +51,6 @@
 }
 
 
-/* ---------------------------------
-   - - -   U t i l i t i e s   - - -
-   ---------------------------------
-*/
-
-
 // This function should be called rather than %AddElement in contexts where the
 // argument might not be less than 2**32-1. ES2015 ToLength semantics mean that
 // this is a concern at basically all callsites.
@@ -174,17 +133,11 @@
   to.AddIndexedProperty = AddIndexedProperty;
   to.MaxSimple = MaxSimple;
   to.MinSimple = MinSimple;
-  to.SameValue = SameValue;
-  to.SameValueZero = SameValueZero;
   to.ToPositiveInteger = ToPositiveInteger;
   to.SpeciesConstructor = SpeciesConstructor;
 });
 
 %InstallToContext([
-  "concat_iterable_to_array_builtin", CONCAT_ITERABLE_TO_ARRAY,
-]);
-
-%InstallToContext([
   "concat_iterable_to_array", ConcatIterableToArray,
 ]);
 
diff --git a/src/js/spread.js b/src/js/spread.js
index 235c91a..82ea839 100644
--- a/src/js/spread.js
+++ b/src/js/spread.js
@@ -18,11 +18,11 @@
 // -------------------------------------------------------------------
 
 function SpreadArguments() {
-  var count = %_ArgumentsLength();
+  var count = arguments.length;
   var args = new InternalArray();
 
   for (var i = 0; i < count; ++i) {
-    var array = %_Arguments(i);
+    var array = arguments[i];
     var length = array.length;
     for (var j = 0; j < length; ++j) {
       args.push(array[j]);
diff --git a/src/js/string.js b/src/js/string.js
index b220038..a401978 100644
--- a/src/js/string.js
+++ b/src/js/string.js
@@ -17,12 +17,11 @@
 var InternalPackedArray = utils.InternalPackedArray;
 var MakeRangeError;
 var MakeTypeError;
-var MathMax;
-var MathMin;
+var MaxSimple;
+var MinSimple;
 var matchSymbol = utils.ImportNow("match_symbol");
-var RegExpExec;
 var RegExpExecNoTests;
-var RegExpLastMatchInfo;
+var replaceSymbol = utils.ImportNow("replace_symbol");
 var searchSymbol = utils.ImportNow("search_symbol");
 var splitSymbol = utils.ImportNow("split_symbol");
 
@@ -31,11 +30,9 @@
   ArrayJoin = from.ArrayJoin;
   MakeRangeError = from.MakeRangeError;
   MakeTypeError = from.MakeTypeError;
-  MathMax = from.MathMax;
-  MathMin = from.MathMin;
-  RegExpExec = from.RegExpExec;
+  MaxSimple = from.MaxSimple;
+  MinSimple = from.MinSimple;
   RegExpExecNoTests = from.RegExpExecNoTests;
-  RegExpLastMatchInfo = from.RegExpLastMatchInfo;
 });
 
 //-------------------------------------------------------------------
@@ -84,41 +81,34 @@
 
 // ECMA-262, section 15.5.4.6
 function StringConcat(other /* and more */) {  // length == 1
+  "use strict";
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.concat");
-  var len = %_ArgumentsLength();
-  var this_as_string = TO_STRING(this);
-  if (len === 1) {
-    return this_as_string + TO_STRING(other);
+  var s = TO_STRING(this);
+  var len = arguments.length;
+  for (var i = 0; i < len; ++i) {
+    s = s + TO_STRING(arguments[i]);
   }
-  var parts = new InternalArray(len + 1);
-  parts[0] = this_as_string;
-  for (var i = 0; i < len; i++) {
-    var part = %_Arguments(i);
-    parts[i + 1] = TO_STRING(part);
-  }
-  return %StringBuilderConcat(parts, len + 1, "");
+  return s;
 }
 
 
 // ECMA-262 section 15.5.4.7
-function StringIndexOfJS(pattern /* position */) {  // length == 1
+function StringIndexOf(pattern, position) {  // length == 1
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.indexOf");
 
   var subject = TO_STRING(this);
   pattern = TO_STRING(pattern);
-  var index = 0;
-  if (%_ArgumentsLength() > 1) {
-    index = %_Arguments(1);  // position
-    index = TO_INTEGER(index);
-    if (index < 0) index = 0;
-    if (index > subject.length) index = subject.length;
-  }
+  var index = TO_INTEGER(position);
+  if (index < 0) index = 0;
+  if (index > subject.length) index = subject.length;
   return %StringIndexOf(subject, pattern, index);
 }
 
+%FunctionSetLength(StringIndexOf, 1);
+
 
 // ECMA-262 section 15.5.4.8
-function StringLastIndexOfJS(pat /* position */) {  // length == 1
+function StringLastIndexOf(pat, pos) {  // length == 1
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.lastIndexOf");
 
   var sub = TO_STRING(this);
@@ -126,16 +116,14 @@
   var pat = TO_STRING(pat);
   var patLength = pat.length;
   var index = subLength - patLength;
-  if (%_ArgumentsLength() > 1) {
-    var position = TO_NUMBER(%_Arguments(1));
-    if (!NUMBER_IS_NAN(position)) {
-      position = TO_INTEGER(position);
-      if (position < 0) {
-        position = 0;
-      }
-      if (position + patLength < subLength) {
-        index = position;
-      }
+  var position = TO_NUMBER(pos);
+  if (!NUMBER_IS_NAN(position)) {
+    position = TO_INTEGER(position);
+    if (position < 0) {
+      position = 0;
+    }
+    if (position + patLength < subLength) {
+      index = position;
     }
   }
   if (index < 0) {
@@ -144,6 +132,8 @@
   return %StringLastIndexOf(sub, pat, index);
 }
 
+%FunctionSetLength(StringLastIndexOf, 1);
+
 
 // ECMA-262 section 15.5.4.9
 //
@@ -180,11 +170,10 @@
 // For now we do nothing, as proper normalization requires big tables.
 // If Intl is enabled, then i18n.js will override it and provide the the
 // proper functionality.
-function StringNormalizeJS() {
+function StringNormalize(formArg) {  // length == 0
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.normalize");
   var s = TO_STRING(this);
 
-  var formArg = %_Arguments(0);
   var form = IS_UNDEFINED(formArg) ? 'NFC' : TO_STRING(formArg);
 
   var NORMALIZATION_FORMS = ['NFC', 'NFD', 'NFKC', 'NFKD'];
@@ -197,6 +186,8 @@
   return s;
 }
 
+%FunctionSetLength(StringNormalize, 0);
+
 
 // This has the same size as the RegExpLastMatchInfo array, and can be used
 // for functions that expect that structure to be returned.  It is used when
@@ -206,14 +197,12 @@
 var reusableMatchInfo = [2, "", "", -1, -1];
 
 
-// ECMA-262, section 15.5.4.11
+// ES6, section 21.1.3.14
 function StringReplace(search, replace) {
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.replace");
 
-  var subject = TO_STRING(this);
-
   // Decision tree for dispatch
-  // .. regexp search
+  // .. regexp search (in src/js/regexp.js, RegExpReplace)
   // .... string replace
   // ...... non-global search
   // ........ empty string replace
@@ -229,40 +218,15 @@
   // ...... function replace
   // ...... string replace (with $-expansion)
 
-  if (IS_REGEXP(search)) {
-    if (!IS_CALLABLE(replace)) {
-      replace = TO_STRING(replace);
-
-      if (!REGEXP_GLOBAL(search)) {
-        // Non-global regexp search, string replace.
-        var match = RegExpExec(search, subject, 0);
-        if (match == null) {
-          search.lastIndex = 0
-          return subject;
-        }
-        if (replace.length == 0) {
-          return %_SubString(subject, 0, match[CAPTURE0]) +
-                 %_SubString(subject, match[CAPTURE1], subject.length)
-        }
-        return ExpandReplacement(replace, subject, RegExpLastMatchInfo,
-                                 %_SubString(subject, 0, match[CAPTURE0])) +
-               %_SubString(subject, match[CAPTURE1], subject.length);
-      }
-
-      // Global regexp search, string replace.
-      search.lastIndex = 0;
-      return %StringReplaceGlobalRegExpWithString(
-          subject, search, replace, RegExpLastMatchInfo);
+  if (!IS_NULL_OR_UNDEFINED(search)) {
+    var replacer = search[replaceSymbol];
+    if (!IS_UNDEFINED(replacer)) {
+      return %_Call(replacer, search, this, replace);
     }
-
-    if (REGEXP_GLOBAL(search)) {
-      // Global regexp search, function replace.
-      return StringReplaceGlobalRegExpWithFunction(subject, search, replace);
-    }
-    // Non-global regexp search, function replace.
-    return StringReplaceNonGlobalRegExpWithFunction(subject, search, replace);
   }
 
+  var subject = TO_STRING(this);
+
   search = TO_STRING(search);
 
   if (search.length == 1 &&
@@ -379,130 +343,6 @@
 }
 
 
-// Compute the string of a given regular expression capture.
-function CaptureString(string, lastCaptureInfo, index) {
-  // Scale the index.
-  var scaled = index << 1;
-  // Compute start and end.
-  var start = lastCaptureInfo[CAPTURE(scaled)];
-  // If start isn't valid, return undefined.
-  if (start < 0) return;
-  var end = lastCaptureInfo[CAPTURE(scaled + 1)];
-  return %_SubString(string, start, end);
-}
-
-
-// TODO(lrn): This array will survive indefinitely if replace is never
-// called again. However, it will be empty, since the contents are cleared
-// in the finally block.
-var reusableReplaceArray = new InternalArray(4);
-
-// Helper function for replacing regular expressions with the result of a
-// function application in String.prototype.replace.
-function StringReplaceGlobalRegExpWithFunction(subject, regexp, replace) {
-  var resultArray = reusableReplaceArray;
-  if (resultArray) {
-    reusableReplaceArray = null;
-  } else {
-    // Inside a nested replace (replace called from the replacement function
-    // of another replace) or we have failed to set the reusable array
-    // back due to an exception in a replacement function. Create a new
-    // array to use in the future, or until the original is written back.
-    resultArray = new InternalArray(16);
-  }
-  var res = %RegExpExecMultiple(regexp,
-                                subject,
-                                RegExpLastMatchInfo,
-                                resultArray);
-  regexp.lastIndex = 0;
-  if (IS_NULL(res)) {
-    // No matches at all.
-    reusableReplaceArray = resultArray;
-    return subject;
-  }
-  var len = res.length;
-  if (NUMBER_OF_CAPTURES(RegExpLastMatchInfo) == 2) {
-    // If the number of captures is two then there are no explicit captures in
-    // the regexp, just the implicit capture that captures the whole match.  In
-    // this case we can simplify quite a bit and end up with something faster.
-    // The builder will consist of some integers that indicate slices of the
-    // input string and some replacements that were returned from the replace
-    // function.
-    var match_start = 0;
-    for (var i = 0; i < len; i++) {
-      var elem = res[i];
-      if (%_IsSmi(elem)) {
-        // Integers represent slices of the original string.
-        if (elem > 0) {
-          match_start = (elem >> 11) + (elem & 0x7ff);
-        } else {
-          match_start = res[++i] - elem;
-        }
-      } else {
-        var func_result = replace(elem, match_start, subject);
-        // Overwrite the i'th element in the results with the string we got
-        // back from the callback function.
-        res[i] = TO_STRING(func_result);
-        match_start += elem.length;
-      }
-    }
-  } else {
-    for (var i = 0; i < len; i++) {
-      var elem = res[i];
-      if (!%_IsSmi(elem)) {
-        // elem must be an Array.
-        // Use the apply argument as backing for global RegExp properties.
-        var func_result = %Apply(replace, UNDEFINED, elem, 0, elem.length);
-        // Overwrite the i'th element in the results with the string we got
-        // back from the callback function.
-        res[i] = TO_STRING(func_result);
-      }
-    }
-  }
-  var result = %StringBuilderConcat(res, len, subject);
-  resultArray.length = 0;
-  reusableReplaceArray = resultArray;
-  return result;
-}
-
-
-function StringReplaceNonGlobalRegExpWithFunction(subject, regexp, replace) {
-  var matchInfo = RegExpExec(regexp, subject, 0);
-  if (IS_NULL(matchInfo)) {
-    regexp.lastIndex = 0;
-    return subject;
-  }
-  var index = matchInfo[CAPTURE0];
-  var result = %_SubString(subject, 0, index);
-  var endOfMatch = matchInfo[CAPTURE1];
-  // Compute the parameter list consisting of the match, captures, index,
-  // and subject for the replace function invocation.
-  // The number of captures plus one for the match.
-  var m = NUMBER_OF_CAPTURES(matchInfo) >> 1;
-  var replacement;
-  if (m == 1) {
-    // No captures, only the match, which is always valid.
-    var s = %_SubString(subject, index, endOfMatch);
-    // Don't call directly to avoid exposing the built-in global object.
-    replacement = replace(s, index, subject);
-  } else {
-    var parameters = new InternalArray(m + 2);
-    for (var j = 0; j < m; j++) {
-      parameters[j] = CaptureString(subject, matchInfo, j);
-    }
-    parameters[j] = index;
-    parameters[j + 1] = subject;
-
-    replacement = %Apply(replace, UNDEFINED, parameters, 0, j + 2);
-  }
-
-  result += replacement;  // The add method converts to string if necessary.
-  // Can't use matchInfo any more from here, since the function could
-  // overwrite it.
-  return result + %_SubString(subject, endOfMatch, subject.length);
-}
-
-
 // ES6 21.1.3.15.
 function StringSearch(pattern) {
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.search");
@@ -719,28 +559,14 @@
 
 
 // ECMA-262, section 15.5.3.2
-function StringFromCharCode(code) {
-  var n = %_ArgumentsLength();
-  if (n == 1) return %_StringCharFromCode(code & 0xffff);
-
-  var one_byte = %NewString(n, NEW_ONE_BYTE_STRING);
-  var i;
-  for (i = 0; i < n; i++) {
-    code = %_Arguments(i) & 0xffff;
-    if (code > 0xff) break;
-    %_OneByteSeqStringSetChar(i, code, one_byte);
+function StringFromCharCode(_) {  // length == 1
+  "use strict";
+  var s = "";
+  var n = arguments.length;
+  for (var i = 0; i < n; ++i) {
+    s += %_StringCharFromCode(arguments[i] & 0xffff);
   }
-  if (i == n) return one_byte;
-  one_byte = %TruncateString(one_byte, i);
-
-  var two_byte = %NewString(n - i, NEW_TWO_BYTE_STRING);
-  %_TwoByteSeqStringSetChar(0, code, two_byte);
-  i++;
-  for (var j = 1; i < n; i++, j++) {
-    code = %_Arguments(i) & 0xffff;
-    %_TwoByteSeqStringSetChar(j, code, two_byte);
-  }
-  return one_byte + two_byte;
+  return s;
 }
 
 
@@ -870,7 +696,7 @@
 
 
 // ES6 draft 04-05-14, section 21.1.3.18
-function StringStartsWith(searchString /* position */) {  // length == 1
+function StringStartsWith(searchString, position) {  // length == 1
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.startsWith");
 
   var s = TO_STRING(this);
@@ -880,16 +706,10 @@
   }
 
   var ss = TO_STRING(searchString);
-  var pos = 0;
-  if (%_ArgumentsLength() > 1) {
-    var arg = %_Arguments(1);  // position
-    if (!IS_UNDEFINED(arg)) {
-      pos = TO_INTEGER(arg);
-    }
-  }
+  var pos = TO_INTEGER(position);
 
   var s_len = s.length;
-  var start = MathMin(MathMax(pos, 0), s_len);
+  var start = MinSimple(MaxSimple(pos, 0), s_len);
   var ss_len = ss.length;
   if (ss_len + start > s_len) {
     return false;
@@ -898,9 +718,11 @@
   return %_SubString(s, start, start + ss_len) === ss;
 }
 
+%FunctionSetLength(StringStartsWith, 1);
+
 
 // ES6 draft 04-05-14, section 21.1.3.7
-function StringEndsWith(searchString /* position */) {  // length == 1
+function StringEndsWith(searchString, position) {  // length == 1
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.endsWith");
 
   var s = TO_STRING(this);
@@ -911,15 +733,9 @@
 
   var ss = TO_STRING(searchString);
   var s_len = s.length;
-  var pos = s_len;
-  if (%_ArgumentsLength() > 1) {
-    var arg = %_Arguments(1);  // position
-    if (!IS_UNDEFINED(arg)) {
-      pos = TO_INTEGER(arg);
-    }
-  }
+  var pos = !IS_UNDEFINED(position) ? TO_INTEGER(position) : s_len
 
-  var end = MathMin(MathMax(pos, 0), s_len);
+  var end = MinSimple(MaxSimple(pos, 0), s_len);
   var ss_len = ss.length;
   var start = end - ss_len;
   if (start < 0) {
@@ -929,9 +745,11 @@
   return %_SubString(s, start, start + ss_len) === ss;
 }
 
+%FunctionSetLength(StringEndsWith, 1);
+
 
 // ES6 draft 04-05-14, section 21.1.3.6
-function StringIncludes(searchString /* position */) {  // length == 1
+function StringIncludes(searchString, position) {  // length == 1
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.includes");
 
   var string = TO_STRING(this);
@@ -941,11 +759,7 @@
   }
 
   searchString = TO_STRING(searchString);
-  var pos = 0;
-  if (%_ArgumentsLength() > 1) {
-    pos = %_Arguments(1);  // position
-    pos = TO_INTEGER(pos);
-  }
+  var pos = TO_INTEGER(position);
 
   var stringLength = string.length;
   if (pos < 0) pos = 0;
@@ -959,6 +773,8 @@
   return %StringIndexOf(string, searchString, pos) !== -1;
 }
 
+%FunctionSetLength(StringIncludes, 1);
+
 
 // ES6 Draft 05-22-2014, section 21.1.3.3
 function StringCodePointAt(pos) {
@@ -984,12 +800,13 @@
 
 // ES6 Draft 05-22-2014, section 21.1.2.2
 function StringFromCodePoint(_) {  // length = 1
+  "use strict";
   var code;
-  var length = %_ArgumentsLength();
+  var length = arguments.length;
   var index;
   var result = "";
   for (index = 0; index < length; index++) {
-    code = %_Arguments(index);
+    code = arguments[index];
     if (!%_IsSmi(code)) {
       code = TO_NUMBER(code);
     }
@@ -1013,8 +830,8 @@
 
 // ES6 Draft 03-17-2015, section 21.1.2.4
 function StringRaw(callSite) {
-  // TODO(caitp): Use rest parameters when implemented
-  var numberOfSubstitutions = %_ArgumentsLength();
+  "use strict";
+  var numberOfSubstitutions = arguments.length;
   var cooked = TO_OBJECT(callSite);
   var raw = TO_OBJECT(cooked.raw);
   var literalSegments = TO_LENGTH(raw.length);
@@ -1024,7 +841,7 @@
 
   for (var i = 1; i < literalSegments; ++i) {
     if (i < numberOfSubstitutions) {
-      result += TO_STRING(%_Arguments(i));
+      result += TO_STRING(arguments[i]);
     }
     result += TO_STRING(raw[i]);
   }
@@ -1058,11 +875,11 @@
   "concat", StringConcat,
   "endsWith", StringEndsWith,
   "includes", StringIncludes,
-  "indexOf", StringIndexOfJS,
-  "lastIndexOf", StringLastIndexOfJS,
+  "indexOf", StringIndexOf,
+  "lastIndexOf", StringLastIndexOf,
   "localeCompare", StringLocaleCompareJS,
   "match", StringMatchJS,
-  "normalize", StringNormalizeJS,
+  "normalize", StringNormalize,
   "repeat", StringRepeat,
   "replace", StringReplace,
   "search", StringSearch,
@@ -1098,9 +915,10 @@
 // Exports
 
 utils.Export(function(to) {
+  to.ExpandReplacement = ExpandReplacement;
   to.StringCharAt = StringCharAtJS;
-  to.StringIndexOf = StringIndexOfJS;
-  to.StringLastIndexOf = StringLastIndexOfJS;
+  to.StringIndexOf = StringIndexOf;
+  to.StringLastIndexOf = StringLastIndexOf;
   to.StringMatch = StringMatchJS;
   to.StringReplace = StringReplace;
   to.StringSlice = StringSlice;
diff --git a/src/js/symbol.js b/src/js/symbol.js
index 5be6e01..ae54369 100644
--- a/src/js/symbol.js
+++ b/src/js/symbol.js
@@ -11,7 +11,6 @@
 // -------------------------------------------------------------------
 // Imports
 
-var GlobalObject = global.Object;
 var GlobalSymbol = global.Symbol;
 var hasInstanceSymbol = utils.ImportNow("has_instance_symbol");
 var isConcatSpreadableSymbol =
@@ -73,22 +72,11 @@
   return %SymbolRegistry().keyFor[symbol];
 }
 
-
-// ES6 19.1.2.8
-function ObjectGetOwnPropertySymbols(obj) {
-  obj = TO_OBJECT(obj);
-
-  return %GetOwnPropertyKeys(obj, PROPERTY_FILTER_SKIP_STRINGS);
-}
-
 // -------------------------------------------------------------------
 
-%FunctionSetPrototype(GlobalSymbol, new GlobalObject());
-
 utils.InstallConstants(GlobalSymbol, [
-  // TODO(rossberg): expose when implemented.
-  // "hasInstance", hasInstanceSymbol,
-  // "isConcatSpreadable", isConcatSpreadableSymbol,
+  "hasInstance", hasInstanceSymbol,
+  "isConcatSpreadable", isConcatSpreadableSymbol,
   "iterator", iteratorSymbol,
   // TODO(yangguo): expose when implemented.
   // "match", matchSymbol,
@@ -108,8 +96,6 @@
 ]);
 
 %AddNamedProperty(
-    GlobalSymbol.prototype, "constructor", GlobalSymbol, DONT_ENUM);
-%AddNamedProperty(
     GlobalSymbol.prototype, toStringTagSymbol, "Symbol", DONT_ENUM | READ_ONLY);
 
 utils.InstallFunctions(GlobalSymbol.prototype, DONT_ENUM | READ_ONLY, [
@@ -121,10 +107,6 @@
   "valueOf", SymbolValueOf
 ]);
 
-utils.InstallFunctions(GlobalObject, DONT_ENUM, [
-  "getOwnPropertySymbols", ObjectGetOwnPropertySymbols
-]);
-
 // -------------------------------------------------------------------
 // Exports
 
diff --git a/src/js/typedarray.js b/src/js/typedarray.js
index fd668a5..3d500a3 100644
--- a/src/js/typedarray.js
+++ b/src/js/typedarray.js
@@ -300,8 +300,10 @@
   var newLength = endInt - beginInt;
   var beginByteOffset =
       %_ArrayBufferViewGetByteOffset(this) + beginInt * ELEMENT_SIZE;
-  return TypedArraySpeciesCreate(this, %TypedArrayGetBuffer(this),
-                                 beginByteOffset, newLength, true);
+  // BUG(v8:4665): For web compatibility, subarray needs to always build an
+  // instance of the default constructor.
+  // TODO(littledan): Switch to the standard or standardize the fix
+  return new GlobalNAME(%TypedArrayGetBuffer(this), beginByteOffset, newLength);
 }
 endmacro
 
@@ -460,6 +462,7 @@
       return;
   }
 }
+%FunctionSetLength(TypedArraySet, 1);
 
 function TypedArrayGetToStringTag() {
   if (!%_IsTypedArray(this)) return;
@@ -564,22 +567,20 @@
 
 
 function TypedArrayComparefn(x, y) {
-  if (IsNaN(x) && IsNaN(y)) {
-    return IsNaN(y) ? 0 : 1;
+  if (x === 0 && x === y) {
+    x = 1 / x;
+    y = 1 / y;
   }
-  if (IsNaN(x)) {
+  if (x < y) {
+    return -1;
+  } else if (x > y) {
+    return 1;
+  } else if (IsNaN(x) && IsNaN(y)) {
+    return IsNaN(y) ? 0 : 1;
+  } else if (IsNaN(x)) {
     return 1;
   }
-  if (x === 0 && x === y) {
-    if (%_IsMinusZero(x)) {
-      if (!%_IsMinusZero(y)) {
-        return -1;
-      }
-    } else if (%_IsMinusZero(y)) {
-      return 1;
-    }
-  }
-  return x - y;
+  return 0;
 }
 
 
@@ -614,7 +615,7 @@
   var length = %_TypedArrayGetLength(this);
 
   return InnerArrayLastIndexOf(this, element, index, length,
-                        %_ArgumentsLength());
+                               arguments.length);
 }
 %FunctionSetLength(TypedArrayLastIndexOf, 1);
 
@@ -678,7 +679,7 @@
 
   var length = %_TypedArrayGetLength(this);
   return InnerArrayReduce(callback, current, this, length,
-                          %_ArgumentsLength());
+                          arguments.length);
 }
 %FunctionSetLength(TypedArrayReduce, 1);
 
@@ -689,7 +690,7 @@
 
   var length = %_TypedArrayGetLength(this);
   return InnerArrayReduceRight(callback, current, this, length,
-                               %_ArgumentsLength());
+                               arguments.length);
 }
 %FunctionSetLength(TypedArrayReduceRight, 1);
 
@@ -750,10 +751,10 @@
 
 // ES6 draft 08-24-14, section 22.2.2.2
 function TypedArrayOf() {
-  var length = %_ArgumentsLength();
+  var length = arguments.length;
   var array = TypedArrayCreate(this, length);
   for (var i = 0; i < length; i++) {
-    array[i] = %_Arguments(i);
+    array[i] = arguments[i];
   }
   return array;
 }
@@ -846,36 +847,6 @@
 
 // --------------------------- DataView -----------------------------
 
-function DataViewConstructor(buffer, byteOffset, byteLength) { // length = 3
-  if (IS_UNDEFINED(new.target)) {
-    throw MakeTypeError(kConstructorNotFunction, "DataView");
-  }
-
-  // TODO(binji): support SharedArrayBuffers?
-  if (!IS_ARRAYBUFFER(buffer)) throw MakeTypeError(kDataViewNotArrayBuffer);
-  if (!IS_UNDEFINED(byteOffset)) {
-    byteOffset = ToPositiveInteger(byteOffset, kInvalidDataViewOffset);
-  }
-  if (!IS_UNDEFINED(byteLength)) {
-    byteLength = TO_INTEGER(byteLength);
-  }
-
-  var bufferByteLength = %_ArrayBufferGetByteLength(buffer);
-
-  var offset = IS_UNDEFINED(byteOffset) ?  0 : byteOffset;
-  if (offset > bufferByteLength) throw MakeRangeError(kInvalidDataViewOffset);
-
-  var length = IS_UNDEFINED(byteLength)
-      ? bufferByteLength - offset
-      : byteLength;
-  if (length < 0 || offset + length > bufferByteLength) {
-    throw new MakeRangeError(kInvalidDataViewLength);
-  }
-  var result = %NewObject(GlobalDataView, new.target);
-  %_DataViewInitialize(result, buffer, offset, length);
-  return result;
-}
-
 function DataViewGetBufferJS() {
   if (!IS_DATAVIEW(this)) {
     throw MakeTypeError(kIncompatibleMethodReceiver, 'DataView.buffer', this);
@@ -917,26 +888,27 @@
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         'DataView.getTYPENAME', this);
   }
-  if (%_ArgumentsLength() < 1) throw MakeTypeError(kInvalidArgument);
+  if (arguments.length < 1) throw MakeTypeError(kInvalidArgument);
   offset = ToPositiveInteger(offset, kInvalidDataViewAccessorOffset);
   return %DataViewGetTYPENAME(this, offset, !!little_endian);
 }
+%FunctionSetLength(DataViewGetTYPENAMEJS, 1);
 
 function DataViewSetTYPENAMEJS(offset, value, little_endian) {
   if (!IS_DATAVIEW(this)) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         'DataView.setTYPENAME', this);
   }
-  if (%_ArgumentsLength() < 2) throw MakeTypeError(kInvalidArgument);
+  if (arguments.length < 2) throw MakeTypeError(kInvalidArgument);
   offset = ToPositiveInteger(offset, kInvalidDataViewAccessorOffset);
   %DataViewSetTYPENAME(this, offset, TO_NUMBER(value), !!little_endian);
 }
+%FunctionSetLength(DataViewSetTYPENAMEJS, 2);
 endmacro
 
 DATA_VIEW_TYPES(DATA_VIEW_GETTER_SETTER)
 
 // Setup the DataView constructor.
-%SetCode(GlobalDataView, DataViewConstructor);
 %FunctionSetPrototype(GlobalDataView, new GlobalObject);
 
 // Set up constructor property on the DataView prototype.
diff --git a/src/js/v8natives.js b/src/js/v8natives.js
index 26447da..5e1a825 100644
--- a/src/js/v8natives.js
+++ b/src/js/v8natives.js
@@ -10,7 +10,6 @@
 // Imports
 
 var GlobalArray = global.Array;
-var GlobalBoolean = global.Boolean;
 var GlobalNumber = global.Number;
 var GlobalObject = global.Object;
 var InternalArray = utils.InternalArray;
@@ -24,7 +23,6 @@
 var ObserveBeginPerformSplice;
 var ObserveEndPerformSplice;
 var ObserveEnqueueSpliceRecord;
-var SameValue = utils.ImportNow("SameValue");
 var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
 
 utils.Import(function(from) {
@@ -545,17 +543,17 @@
     if ((IsGenericDescriptor(desc) ||
          IsDataDescriptor(desc) == IsDataDescriptor(current)) &&
         (!desc.hasEnumerable() ||
-         SameValue(desc.isEnumerable(), current.isEnumerable())) &&
+         %SameValue(desc.isEnumerable(), current.isEnumerable())) &&
         (!desc.hasConfigurable() ||
-         SameValue(desc.isConfigurable(), current.isConfigurable())) &&
+         %SameValue(desc.isConfigurable(), current.isConfigurable())) &&
         (!desc.hasWritable() ||
-         SameValue(desc.isWritable(), current.isWritable())) &&
+         %SameValue(desc.isWritable(), current.isWritable())) &&
         (!desc.hasValue() ||
-         SameValue(desc.getValue(), current.getValue())) &&
+         %SameValue(desc.getValue(), current.getValue())) &&
         (!desc.hasGetter() ||
-         SameValue(desc.getGet(), current.getGet())) &&
+         %SameValue(desc.getGet(), current.getGet())) &&
         (!desc.hasSetter() ||
-         SameValue(desc.getSet(), current.getSet()))) {
+         %SameValue(desc.getSet(), current.getSet()))) {
       return true;
     }
     if (!current.isConfigurable()) {
@@ -594,7 +592,7 @@
             }
           }
           if (!currentIsWritable && desc.hasValue() &&
-              !SameValue(desc.getValue(), current.getValue())) {
+              !%SameValue(desc.getValue(), current.getValue())) {
             if (should_throw) {
               throw MakeTypeError(kRedefineDisallowed, p);
             } else {
@@ -605,14 +603,14 @@
         // Step 11
         if (IsAccessorDescriptor(desc) && IsAccessorDescriptor(current)) {
           if (desc.hasSetter() &&
-              !SameValue(desc.getSet(), current.getSet())) {
+              !%SameValue(desc.getSet(), current.getSet())) {
             if (should_throw) {
               throw MakeTypeError(kRedefineDisallowed, p);
             } else {
               return false;
             }
           }
-          if (desc.hasGetter() && !SameValue(desc.getGet(),current.getGet())) {
+          if (desc.hasGetter() && !%SameValue(desc.getGet(),current.getGet())) {
             if (should_throw) {
               throw MakeTypeError(kRedefineDisallowed, p);
             } else {
@@ -772,19 +770,6 @@
 }
 
 
-// ES6 section 19.1.2.6
-function ObjectGetOwnPropertyDescriptor(obj, p) {
-  return %GetOwnProperty(obj, p);
-}
-
-
-// ES5 section 15.2.3.4.
-function ObjectGetOwnPropertyNames(obj) {
-  obj = TO_OBJECT(obj);
-  return %GetOwnPropertyKeys(obj, PROPERTY_FILTER_SKIP_SYMBOLS);
-}
-
-
 // ES5 section 15.2.3.6.
 function ObjectDefineProperty(obj, p, attributes) {
   // The new pure-C++ implementation doesn't support O.o.
@@ -802,11 +787,6 @@
 }
 
 
-function GetOwnEnumerablePropertyNames(object) {
-  return %GetOwnPropertyKeys(object, PROPERTY_FILTER_ONLY_ENUMERABLE);
-}
-
-
 // ES5 section 15.2.3.7.
 function ObjectDefineProperties(obj, properties) {
   // The new pure-C++ implementation doesn't support O.o.
@@ -816,7 +796,7 @@
       throw MakeTypeError(kCalledOnNonObject, "Object.defineProperties");
     }
     var props = TO_OBJECT(properties);
-    var names = GetOwnEnumerablePropertyNames(props);
+    var names = %GetOwnPropertyKeys(props, PROPERTY_FILTER_ONLY_ENUMERABLE);
     var descriptors = new InternalArray();
     for (var i = 0; i < names.length; i++) {
       descriptors.push(ToPropertyDescriptor(props[names[i]]));
@@ -889,65 +869,13 @@
   "defineProperties", ObjectDefineProperties,
   "getPrototypeOf", ObjectGetPrototypeOf,
   "setPrototypeOf", ObjectSetPrototypeOf,
-  "getOwnPropertyDescriptor", ObjectGetOwnPropertyDescriptor,
-  "getOwnPropertyNames", ObjectGetOwnPropertyNames,
   // getOwnPropertySymbols is added in symbol.js.
-  "is", SameValue,  // ECMA-262, Edition 6, section 19.1.2.10
+  // is is added in bootstrapper.cc.
   // deliverChangeRecords, getNotifier, observe and unobserve are added
   // in object-observe.js.
 ]);
 
 
-// ----------------------------------------------------------------------------
-// Boolean
-
-function BooleanConstructor(x) {
-  // TODO(bmeurer): Move this to toplevel.
-  "use strict";
-  if (!IS_UNDEFINED(new.target)) {
-    %_SetValueOf(this, TO_BOOLEAN(x));
-  } else {
-    return TO_BOOLEAN(x);
-  }
-}
-
-
-function BooleanToString() {
-  // NOTE: Both Boolean objects and values can enter here as
-  // 'this'. This is not as dictated by ECMA-262.
-  var b = this;
-  if (!IS_BOOLEAN(b)) {
-    if (!IS_BOOLEAN_WRAPPER(b)) {
-      throw MakeTypeError(kNotGeneric, 'Boolean.prototype.toString');
-    }
-    b = %_ValueOf(b);
-  }
-  return b ? 'true' : 'false';
-}
-
-
-function BooleanValueOf() {
-  // NOTE: Both Boolean objects and values can enter here as
-  // 'this'. This is not as dictated by ECMA-262.
-  if (!IS_BOOLEAN(this) && !IS_BOOLEAN_WRAPPER(this)) {
-    throw MakeTypeError(kNotGeneric, 'Boolean.prototype.valueOf');
-  }
-  return %_ValueOf(this);
-}
-
-
-// ----------------------------------------------------------------------------
-
-%SetCode(GlobalBoolean, BooleanConstructor);
-%FunctionSetPrototype(GlobalBoolean, new GlobalBoolean(false));
-%AddNamedProperty(GlobalBoolean.prototype, "constructor", GlobalBoolean,
-                  DONT_ENUM);
-
-utils.InstallFunctions(GlobalBoolean.prototype, DONT_ENUM, [
-  "toString", BooleanToString,
-  "valueOf", BooleanValueOf
-]);
-
 
 // ----------------------------------------------------------------------------
 // Number