Crankshaft: Recognize (i >>> 0) === i for integer32 inputs and replace

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
===================================================================
--- src/hydrogen-instructions.h	(revision 14364)
+++ src/hydrogen-instructions.h	(working copy)
@@ -3910,6 +3910,8 @@
 
   virtual void AddInformativeDefinitions();
 
+  virtual HValue* Canonicalize();
+
   DECLARE_CONCRETE_INSTRUCTION(CompareIDAndBranch)
 
  private:
@@ -4613,7 +4615,7 @@
     if (right()->IsInteger32Constant()) {
       if (decomposition->Apply(left(), 0, right()->GetInteger32Constant())) {
         // This is intended to look for HAdd and HSub, to handle compounds
-        // like ((base + offset) >> scale) with one single decomposition.
+        // like ((base + offset) >>> scale) with one single decomposition.
         left()->TryDecompose(decomposition);
         return true;
       }