Revert "Revert "Upgrade to 5.0.71.48"" DO NOT MERGE

This reverts commit f2e3994fa5148cc3d9946666f0b0596290192b0e,
and updates the x64 makefile properly so it doesn't break that
build.

FPIIM-449

Change-Id: Ib83e35bfbae6af627451c926a9650ec57c045605
(cherry picked from commit 109988c7ccb6f3fd1a58574fa3dfb88beaef6632)
diff --git a/test/unittests/interpreter/interpreter-assembler-unittest.h b/test/unittests/interpreter/interpreter-assembler-unittest.h
new file mode 100644
index 0000000..321c724
--- /dev/null
+++ b/test/unittests/interpreter/interpreter-assembler-unittest.h
@@ -0,0 +1,57 @@
+// Copyright 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.
+
+#ifndef V8_UNITTESTS_INTERPRETER_INTERPRETER_ASSEMBLER_UNITTEST_H_
+#define V8_UNITTESTS_INTERPRETER_INTERPRETER_ASSEMBLER_UNITTEST_H_
+
+#include "src/compiler/machine-operator.h"
+#include "src/interpreter/interpreter-assembler.h"
+#include "test/unittests/test-utils.h"
+#include "testing/gmock-support.h"
+
+namespace v8 {
+namespace internal {
+namespace interpreter {
+
+using ::testing::Matcher;
+
+class InterpreterAssemblerTest : public TestWithIsolateAndZone {
+ public:
+  InterpreterAssemblerTest() {}
+  ~InterpreterAssemblerTest() override {}
+
+  class InterpreterAssemblerForTest final : public InterpreterAssembler {
+   public:
+    InterpreterAssemblerForTest(InterpreterAssemblerTest* test,
+                                Bytecode bytecode)
+        : InterpreterAssembler(test->isolate(), test->zone(), bytecode) {}
+    ~InterpreterAssemblerForTest() override {}
+
+    Matcher<compiler::Node*> IsLoad(
+        const Matcher<compiler::LoadRepresentation>& rep_matcher,
+        const Matcher<compiler::Node*>& base_matcher,
+        const Matcher<compiler::Node*>& index_matcher);
+    Matcher<compiler::Node*> IsStore(
+        const Matcher<compiler::StoreRepresentation>& rep_matcher,
+        const Matcher<compiler::Node*>& base_matcher,
+        const Matcher<compiler::Node*>& index_matcher,
+        const Matcher<compiler::Node*>& value_matcher);
+
+    Matcher<compiler::Node*> IsBytecodeOperand(int offset);
+    Matcher<compiler::Node*> IsBytecodeOperandSignExtended(int offset);
+    Matcher<compiler::Node*> IsBytecodeOperandShort(int offset);
+    Matcher<compiler::Node*> IsBytecodeOperandShortSignExtended(int offset);
+
+    using InterpreterAssembler::graph;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(InterpreterAssemblerForTest);
+  };
+};
+
+}  // namespace interpreter
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_UNITTESTS_INTERPRETER_INTERPRETER_ASSEMBLER_UNITTEST_H_