[es6] Implement spec compliant ToPrimitive in the runtime.

src/full-codegen/x64/full-codegen-x64.cc

 // Copyright 2012 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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/compiler.h"
@@ skipping 3335 matching lines @@
   __ imulp(rcx, rcx, Immediate(DescriptorArray::kDescriptorSize));
   __ leap(rcx,
           Operand(r8, rcx, times_pointer_size, DescriptorArray::kFirstOffset));
   // Calculate location of the first key name.
   __ addp(r8, Immediate(DescriptorArray::kFirstOffset));
   // Loop through all the keys in the descriptor array. If one of these is the
   // internalized string "valueOf" the result is false.
   __ jmp(&entry);
   __ bind(&loop);
   __ movp(rdx, FieldOperand(r8, 0));
-  __ Cmp(rdx, isolate()->factory()->value_of_string());
+  __ CompareRoot(rdx, Heap::kvalueOf_stringRootIndex);
   __ j(equal, if_false);
   __ addp(r8, Immediate(DescriptorArray::kDescriptorSize * kPointerSize));
   __ bind(&entry);
   __ cmpp(r8, rcx);
   __ j(not_equal, &loop);
 
   __ bind(&done);
 
   // Set the bit in the map to indicate that there is no local valueOf field.
   __ orp(FieldOperand(rbx, Map::kBitField2Offset),
@@ skipping 1898 matching lines @@
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64