Refactor optimized in hydrogen only runtime functions.

src/arm/lithium-codegen-arm.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 4445 matching lines @@
   // DoStringCharCodeAt above.
   if (instr->index()->IsConstantOperand()) {
     int const_index = ToInteger32(LConstantOperand::cast(instr->index()));
     __ mov(scratch, Operand(Smi::FromInt(const_index)));
     __ push(scratch);
   } else {
     Register index = ToRegister(instr->index());
     __ SmiTag(index);
     __ push(index);
   }
-  CallRuntimeFromDeferred(Runtime::kStringCharCodeAt, 2, instr,
+  CallRuntimeFromDeferred(Runtime::kHiddenStringCharCodeAt, 2, instr,
                           instr->context());
   __ AssertSmi(r0);
   __ SmiUntag(r0);
   __ StoreToSafepointRegisterSlot(r0, result);
 }
 
 
 void LCodeGen::DoStringCharFromCode(LStringCharFromCode* instr) {
   class DeferredStringCharFromCode V8_FINAL : public LDeferredCode {
    public:
@@ skipping 1261 matching lines @@
   __ sub(scratch, result, Operand::PointerOffsetFromSmiKey(index));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal