[es6] Implement spec compliant ToPrimitive in the runtime.

test/cctest/test-heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 56 matching lines @@
   SIMD128_TYPES(SIMD128_TYPE)
 #undef SIMD128_TYPE
   CheckMap(heap->fixed_array_map(), FIXED_ARRAY_TYPE, kVariableSizeSentinel);
   CheckMap(heap->string_map(), STRING_TYPE, kVariableSizeSentinel);
 }
 
 
 static void CheckOddball(Isolate* isolate, Object* obj, const char* string) {
   CHECK(obj->IsOddball());
   Handle<Object> handle(obj, isolate);
-  Object* print_string =
-      *Execution::ToString(isolate, handle).ToHandleChecked();
+  Object* print_string = *Object::ToString(isolate, handle).ToHandleChecked();
   CHECK(String::cast(print_string)->IsUtf8EqualTo(CStrVector(string)));
 }
 
 
 static void CheckSmi(Isolate* isolate, int value, const char* string) {
   Handle<Object> handle(Smi::FromInt(value), isolate);
-  Object* print_string =
-      *Execution::ToString(isolate, handle).ToHandleChecked();
+  Object* print_string = *Object::ToString(isolate, handle).ToHandleChecked();
   CHECK(String::cast(print_string)->IsUtf8EqualTo(CStrVector(string)));
 }
 
 
 static void CheckNumber(Isolate* isolate, double value, const char* string) {
   Handle<Object> number = isolate->factory()->NewNumber(value);
   CHECK(number->IsNumber());
   Handle<Object> print_string =
-      Execution::ToString(isolate, number).ToHandleChecked();
+      Object::ToString(isolate, number).ToHandleChecked();
   CHECK(String::cast(*print_string)->IsUtf8EqualTo(CStrVector(string)));
 }
 
 
 static void CheckFindCodeObject(Isolate* isolate) {
   // Test FindCodeObject
 #define __ assm.
 
   Assembler assm(isolate, NULL, 0);
 
@@ skipping 6554 matching lines @@
   {
     SharedFunctionInfo::Iterator iterator(isolate);
     while (iterator.Next()) sfi_count--;
   }
 
   CHECK_EQ(0, sfi_count);
 }
 
 }  // namespace internal
 }  // namespace v8