Fixing issue 1898 (using HChange outside the insert-representation-changes phase).

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 1113 matching lines @@
     ASSERT(!value->representation().Equals(to));
     set_representation(to);
     set_type(HType::TaggedNumber());
     SetFlag(kUseGVN);
     if (deoptimize_on_undefined) SetFlag(kDeoptimizeOnUndefined);
     if (is_truncating) SetFlag(kTruncatingToInt32);
   }
 
   virtual HValue* EnsureAndPropagateNotMinusZero(BitVector* visited);
   virtual HType CalculateInferredType();
+  virtual HValue* Canonicalize();
 
   Representation from() { return value()->representation(); }
   Representation to() { return representation(); }
   bool deoptimize_on_undefined() const {
     return CheckFlag(kDeoptimizeOnUndefined);
   }
   bool deoptimize_on_minus_zero() const {
     return CheckFlag(kBailoutOnMinusZero);
   }
   virtual Representation RequiredInputRepresentation(int index) {
@@ skipping 3378 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(In)
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_