Fix Mac build broken by r12733.

runtime/vm/intermediate_language.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 1763 matching lines @@
   virtual RawAbstractType* CompileType() const {
     return Type::SmiType();
   }
 
   virtual bool CanDeoptimize() const { return false; }
 
   virtual bool HasSideEffect() const { return false; }
 
   virtual intptr_t ResultCid() const { return kSmiCid; }
 
-  virtual bool AttributesEqual(Definition* other) const {
+  virtual bool AttributesEqual(Instruction* other) const {
     UNREACHABLE();
     return false;
   }
 
   virtual void PrintOperandsTo(BufferFormatter* f) const;
 
   Value* value() const { return inputs_[0]; }
   Range* constraint() const { return constraint_; }
 
   virtual bool InferRange();
@@ skipping 2171 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_