[es6] Implement spec compliant ToPrimitive in the runtime.

src/full-codegen/arm64/full-codegen-arm64.cc

 // Copyright 2013 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_ARM64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/compiler.h"
@@ skipping 3151 matching lines @@
   __ Add(descriptors, descriptors,
          DescriptorArray::kFirstOffset - kHeapObjectTag);
   // Calculate the end of the descriptor array.
   __ Add(descriptors_end, descriptors,
          Operand(descriptors_length, LSL, kPointerSizeLog2));
 
   // Loop through all the keys in the descriptor array. If one of these is the
   // string "valueOf" the result is false.
   Register valueof_string = x1;
   int descriptor_size = DescriptorArray::kDescriptorSize * kPointerSize;
-  __ Mov(valueof_string, Operand(isolate()->factory()->value_of_string()));
+  __ LoadRoot(valueof_string, Heap::kvalueOf_stringRootIndex);
   __ Bind(&loop);
   __ Ldr(x15, MemOperand(descriptors, descriptor_size, PostIndex));
   __ Cmp(x15, valueof_string);
   __ B(eq, if_false);
   __ Cmp(descriptors, descriptors_end);
   __ B(ne, &loop);
 
   __ Bind(&done);
 
   // Set the bit in the map to indicate that there is no local valueOf field.
@@ skipping 2183 matching lines @@
   }
 
   return INTERRUPT;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64