Roll V8 back to 3.6

Roll back to V8 3.6 to fix x86 build, we don't have ucontext.h.

This reverts commits:
5d4cdbf7a67d3662fa0bee4efdb7edd8daec9b0b
c7cc028aaeedbbfa11c11d0b7b243b3d9e837ed9
592a9fc1d8ea420377a2e7efd0600e20b058be2b

Bug: 5688872
Change-Id: Ic961bb5e65b778e98bbfb71cce71d99fa949e995
diff --git a/test/cctest/test-regexp.cc b/test/cctest/test-regexp.cc
index d941d0f..89a9112 100644
--- a/test/cctest/test-regexp.cc
+++ b/test/cctest/test-regexp.cc
@@ -449,7 +449,6 @@
     case 0xA0:
     case 0x2028:
     case 0x2029:
-    case 0xFEFF:
       return true;
     default:
       return unibrow::Space::Is(c);
@@ -531,7 +530,7 @@
   typedef int Key;
   typedef int Value;
   static const int kNoKey;
-  static int NoValue() { return 0; }
+  static const int kNoValue;
   static inline int Compare(int a, int b) {
     if (a < b)
       return -1;
@@ -544,6 +543,7 @@
 
 
 const int TestConfig::kNoKey = 0;
+const int TestConfig::kNoValue = 0;
 
 
 static unsigned PseudoRandom(int i, int j) {
@@ -837,8 +837,7 @@
   Handle<Code> code = Handle<Code>::cast(code_object);
 
   int captures[4] = {42, 37, 87, 117};
-  const uc16 input_data[6] = {'f', 'o', 'o', 'f', 'o',
-                              static_cast<uc16>('\xa0')};
+  const uc16 input_data[6] = {'f', 'o', 'o', 'f', 'o', '\xa0'};
   Handle<String> input =
       factory->NewStringFromTwoByte(Vector<const uc16>(input_data, 6));
   Handle<SeqTwoByteString> seq_input = Handle<SeqTwoByteString>::cast(input);
@@ -858,8 +857,7 @@
   CHECK_EQ(-1, captures[2]);
   CHECK_EQ(-1, captures[3]);
 
-  const uc16 input_data2[9] = {'b', 'a', 'r', 'b', 'a', 'r', 'b', 'a',
-                               static_cast<uc16>('\xa0')};
+  const uc16 input_data2[9] = {'b', 'a', 'r', 'b', 'a', 'r', 'b', 'a', '\xa0'};
   input = factory->NewStringFromTwoByte(Vector<const uc16>(input_data2, 9));
   seq_input = Handle<SeqTwoByteString>::cast(input);
   start_adr = seq_input->GetCharsAddress();