Replace a set of Hydrogen instructions with rotate instructions on ARM

src/hydrogen.h

Index: src/hydrogen.h
===================================================================
--- src/hydrogen.h	(revision 12582)
+++ src/hydrogen.h	(working copy)
@@ -269,7 +269,9 @@
   void EliminateRedundantBoundsChecks();
   void DehoistSimpleArrayIndexComputations();
   void PropagateDeoptimizingMark();
+  void ReplaceWithRor();
 
+
   // Returns false if there are phi-uses of the arguments-object
   // which are not supported by the optimizing compiler.
   bool CheckArgumentsPhiUses();
@@ -383,6 +385,8 @@
   void InitializeInferredTypes(int from_inclusive, int to_inclusive);
   void CheckForBackEdge(HBasicBlock* block, HBasicBlock* successor);
   void EliminateRedundantBoundsChecks(HBasicBlock* bb, BoundsCheckTable* table);
+  bool TryRotateLeft(HInstruction* current);
+  bool TryRotateRight(HInstruction* current);
 
   Isolate* isolate_;
   int next_block_id_;