Rollback of r17108, r17106, r17104 in trunk branch.

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 749 matching lines @@
   }
   int UseCount() const;
 
   // Mark this HValue as dead and to be removed from other HValues' use lists.
   void Kill();
 
   int flags() const { return flags_; }
   void SetFlag(Flag f) { flags_ |= (1 << f); }
   void ClearFlag(Flag f) { flags_ &= ~(1 << f); }
   bool CheckFlag(Flag f) const { return (flags_ & (1 << f)) != 0; }
-  void CopyFlag(Flag f, HValue* other) {
-    if (other->CheckFlag(f)) SetFlag(f);
-  }
 
   // Returns true if the flag specified is set for all uses, false otherwise.
   bool CheckUsesForFlag(Flag f) const;
   // Same as before and the first one without the flag is returned in value.
   bool CheckUsesForFlag(Flag f, HValue** value) const;
   // Returns true if the flag specified is set for all uses, and this set
   // of uses is non-empty.
   bool HasAtLeastOneUseWithFlagAndNoneWithout(Flag f) const;
 
   GVNFlagSet gvn_flags() const { return gvn_flags_; }
@@ skipping 6351 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_