Skip canonicalization check in LStoreKeyedFastDoubleElement when it is not needed:

src/x64/lithium-x64.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 1689 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(StoreKeyedFastDoubleElement,
                                "store-keyed-fast-double-element")
   DECLARE_HYDROGEN_ACCESSOR(StoreKeyedFastDoubleElement)
 
   virtual void PrintDataTo(StringStream* stream);
 
   LOperand* elements() { return inputs_[0]; }
   LOperand* key() { return inputs_[1]; }
   LOperand* value() { return inputs_[2]; }
+
+  bool NeedsCanonicalization() { return hydrogen()->NeedsCanonicalization(); }
 };
 
 
 class LStoreKeyedSpecializedArrayElement: public LTemplateInstruction<0, 3, 0> {
  public:
   LStoreKeyedSpecializedArrayElement(LOperand* external_pointer,
                                      LOperand* key,
                                      LOperand* val) {
     inputs_[0] = external_pointer;
     inputs_[1] = key;
@@ skipping 649 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::int
 
 #endif  // V8_X64_LITHIUM_X64_H_