Give uses within a loop a greater weight when doing representation inference.

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 538 matching lines @@
   HValue() : block_(NULL),
              id_(kNoNumber),
              type_(HType::Tagged()),
              use_list_(NULL),
              range_(NULL),
              flags_(0) {}
   virtual ~HValue() {}
 
   HBasicBlock* block() const { return block_; }
   void SetBlock(HBasicBlock* block);
+  int LoopWeight() const;
 
   int id() const { return id_; }
   void set_id(int id) { id_ = id; }
 
   HUseIterator uses() const { return HUseIterator(use_list_); }
 
   virtual bool EmitAtUses() { return false; }
   Representation representation() const { return representation_; }
   void ChangeRepresentation(Representation r) {
     // Representation was already set and is allowed to be changed.
@@ skipping 3679 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(In)
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_