Turn dead code elimination into a proper HPhase.

src/hydrogen.h

 // Copyright 2012 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 288 matching lines @@
   void ComputeMinusZeroChecks();
   bool ProcessArgumentsObject();
   void EliminateRedundantPhis();
   void Canonicalize();
   void OrderBlocks();
   void AssignDominators();
   void SetupInformativeDefinitions();
   void EliminateRedundantBoundsChecks();
   void DehoistSimpleArrayIndexComputations();
   void RestoreActualValues();
-  void DeadCodeElimination(const char *phase_name);
   void PropagateDeoptimizingMark();
   void AnalyzeAndPruneEnvironmentLiveness();
 
   // Returns false if there are phi-uses of the arguments-object
   // which are not supported by the optimizing compiler.
   bool CheckArgumentsPhiUses();
 
   // Returns false if there are phi-uses of an uninitialized const
   // which are not supported by the optimizing compiler.
   bool CheckConstPhiUses();
@@ skipping 124 matching lines @@
  private:
   HConstant* GetConstant(SetOncePointer<HConstant>* pointer,
                          int32_t integer_value);
 
   template<class Phase>
   void Run() {
     Phase phase(this);
     phase.Run();
   }
 
-  void MarkLive(HValue* ref, HValue* instr, ZoneList<HValue*>* worklist);
-  void MarkLiveInstructions();
-  void RemoveDeadInstructions();
   void MarkAsDeoptimizingRecursively(HBasicBlock* block);
   void NullifyUnreachableInstructions();
   void InsertTypeConversions(HInstruction* instr);
   void PropagateMinusZeroChecks(HValue* value, BitVector* visited);
   void RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi);
   void InsertRepresentationChangeForUse(HValue* value,
                                         HValue* use_value,
                                         int use_index,
                                         Representation to);
   void InsertRepresentationChangesForValue(HValue* value);
@@ skipping 1638 matching lines @@
   EmbeddedVector<char, 64> filename_;
   HeapStringAllocator string_allocator_;
   StringStream trace_;
   int indent_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_