Refactor optimized in hydrogen only runtime functions.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 4443 matching lines @@
   STATIC_ASSERT(String::kMaxLength <= Smi::kMaxValue);
   if (instr->index()->IsConstantOperand()) {
     int32_t const_index = ToInteger32(LConstantOperand::cast(instr->index()));
     __ Push(Smi::FromInt(const_index));
   } else {
     Register index = ToRegister(instr->index());
     __ Integer32ToSmi(index, index);
     __ Push(index);
   }
   CallRuntimeFromDeferred(
-      Runtime::kStringCharCodeAt, 2, instr, instr->context());
+      Runtime::kHiddenStringCharCodeAt, 2, instr, instr->context());
   __ AssertSmi(rax);
   __ SmiToInteger32(rax, rax);
   __ StoreToSafepointRegisterSlot(result, rax);
 }
 
 
 void LCodeGen::DoStringCharFromCode(LStringCharFromCode* instr) {
   class DeferredStringCharFromCode V8_FINAL : public LDeferredCode {
    public:
     DeferredStringCharFromCode(LCodeGen* codegen, LStringCharFromCode* instr)
@@ skipping 1175 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64