Fix dependency of loading the heap-number for a double-field store to be the mapcheck.

src/hydrogen-instructions.h

 // 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 5581 matching lines @@
   }
 };
 
 
 class HLoadNamedField V8_FINAL : public HTemplateInstruction<1> {
  public:
   DECLARE_INSTRUCTION_FACTORY_P2(HLoadNamedField, HValue*, HObjectAccess);
 
   HValue* object() { return OperandAt(0); }
   bool HasTypeCheck() { return object()->IsCheckMaps(); }
-  void ClearTypeCheck() { SetOperandAt(0, object()->ActualValue()); }
   HObjectAccess access() const { return access_; }
   Representation field_representation() const {
       return access_.representation();
   }
 
   virtual bool HasEscapingOperandAt(int index) V8_OVERRIDE { return false; }
   virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
     if (index == 0 && access().IsExternalMemory()) {
       // object must be external in case of external memory access
       return Representation::External();
@@ skipping 1180 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_