Silence warning from presubmit lint script

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 746 matching lines @@
   // added to the graph. Reflects creation order.
   int id_;
 
   Representation representation_;
   HType type_;
   HUseListNode* use_list_;
   Range* range_;
   int flags_;
   GVNFlagSet gvn_flags_;
 
+ private:
   DISALLOW_COPY_AND_ASSIGN(HValue);
 };
 
 
 class HInstruction: public HValue {
  public:
   HInstruction* next() const { return next_; }
   HInstruction* previous() const { return previous_; }
 
   virtual void PrintTo(StringStream* stream);
@@ skipping 3780 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(In)
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_