Turn mark deoptimize on undefined into a proper HPhase.

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index 895b9849c97d36c16bb6ecdbd6c93f1eb951eb2c..df2b1c789b43ffa6eb9de00d1acfa86985b849c5 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -316,7 +316,6 @@ class HGraph: public ZoneObject {
   HEnvironment* start_environment() const { return start_environment_; }
 
   void FinalizeUniqueValueIds();
-  void MarkDeoptimizeOnUndefined();
   bool ProcessArgumentsObject();
   void OrderBlocks();
   void AssignDominators();
@@ -464,7 +463,6 @@ class HGraph: public ZoneObject {
     phase.Run();
   }
 
-  void RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi);
   void CheckForBackEdge(HBasicBlock* block, HBasicBlock* successor);
   void SetupInformativeDefinitionsInBlock(HBasicBlock* block);
   void SetupInformativeDefinitionsRecursively(HBasicBlock* block);