Simplify redundant phi elimination and use during canonicalization too.

src/hydrogen-redundant-phi.h

Index: src/hydrogen-redundant-phi.h
diff --git a/src/hydrogen-redundant-phi.h b/src/hydrogen-redundant-phi.h
index 6291fa5b7871e4d0612e8e680ce4e5e7db8f6685..960ae69c95f15b9dfaad4ae2322fa9a7a82a5a1f 100644
--- a/src/hydrogen-redundant-phi.h
+++ b/src/hydrogen-redundant-phi.h
@@ -42,8 +42,11 @@ class HRedundantPhiEliminationPhase : public HPhase {
       : HPhase("H_Redundant phi elimination", graph) { }
 
   void Run();
+  void ProcessBlock(HBasicBlock* block);
 
  private:
+  void ProcessPhis(const ZoneList<HPhi*>* phis);
+
   DISALLOW_COPY_AND_ASSIGN(HRedundantPhiEliminationPhase);
 };