Add boolean flag to HChange and LNumberUntagD to not convert undefined to NaN.

src/x64/lithium-codegen-x64.h

 // Copyright 2011 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 231 matching lines @@
                                     int deoptimization_index);
   void RecordPosition(int position);
   int LastSafepointEnd() {
     return static_cast<int>(safepoints_.GetPcAfterGap());
   }
 
   static Condition TokenToCondition(Token::Value op, bool is_unsigned);
   void EmitGoto(int block, LDeferredCode* deferred_stack_check = NULL);
   void EmitBranch(int left_block, int right_block, Condition cc);
   void EmitCmpI(LOperand* left, LOperand* right);
-  void EmitNumberUntagD(Register input, XMMRegister result, LEnvironment* env);
+  void EmitNumberUntagD(Register input,
+                        XMMRegister result,
+                        bool deoptimize_on_undefined,
+                        LEnvironment* env);
 
   // Emits optimized code for typeof x == "y".  Modifies input register.
   // Returns the condition on which a final split to
   // true and false label should be made, to optimize fallthrough.
   Condition EmitTypeofIs(Label* true_label, Label* false_label,
                          Register input, Handle<String> type_name);
 
   // Emits optimized code for %_IsObject(x).  Preserves input register.
   // Returns the condition on which a final split to
   // true and false label should be made, to optimize fallthrough.
@@ skipping 95 matching lines @@
  private:
   LCodeGen* codegen_;
   Label entry_;
   Label exit_;
   Label* external_exit_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_LITHIUM_CODEGEN_X64_H_