Fix error in postfix ++ in Crankshaft.

src/hydrogen-instructions.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 83 matching lines @@
   V(CompareMap)                                \
   V(CompareSymbolEq)                           \
   V(Constant)                                  \
   V(Context)                                   \
   V(DeleteProperty)                            \
   V(Deoptimize)                                \
   V(Div)                                       \
   V(EnterInlined)                              \
   V(ExternalArrayLength)                       \
   V(FixedArrayLength)                          \
+  V(ForceRepresentation)                       \
   V(FunctionLiteral)                           \
   V(GetCachedArrayIndex)                       \
   V(GlobalObject)                              \
   V(GlobalReceiver)                            \
   V(Goto)                                      \
   V(HasInstanceType)                           \
   V(HasCachedArrayIndex)                       \
   V(In)                                        \
   V(InstanceOf)                                \
   V(InstanceOfKnownGlobal)                     \
@@ skipping 888 matching lines @@
   }
 
   virtual Representation RequiredInputRepresentation(int index) const {
     return Representation::Tagged();
   }
 
   DECLARE_CONCRETE_INSTRUCTION(Throw)
 };
 
 
+class HForceRepresentation: public HTemplateInstruction<1> {
+ public:
+  HForceRepresentation(HValue* value, Representation required_representation) {
+    SetOperandAt(0, value);
+    set_representation(required_representation);
+  }
+
+  HValue* value() { return OperandAt(0); }
+
+  virtual HValue* EnsureAndPropagateNotMinusZero(BitVector* visited);
+
+  virtual Representation RequiredInputRepresentation(int index) const {
+    return representation();  // Same as the output representation.
+  }
+
+  DECLARE_CONCRETE_INSTRUCTION(ForceRepresentation)
+};
+
+
 class HChange: public HUnaryOperation {
  public:
   HChange(HValue* value,
           Representation from,
           Representation to,
           bool is_truncating)
       : HUnaryOperation(value), from_(from) {
     ASSERT(!from.IsNone() && !to.IsNone());
     ASSERT(!from.Equals(to));
     set_representation(to);
@@ skipping 2914 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(In)
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_