Move Hydrogen and Lithium to src/crankshaft/

src/hydrogen-dce.h

-// Copyright 2013 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_HYDROGEN_DCE_H_
-#define V8_HYDROGEN_DCE_H_
-
-#include "src/hydrogen.h"
-
-namespace v8 {
-namespace internal {
-
-
-class HDeadCodeEliminationPhase : public HPhase {
- public:
-  explicit HDeadCodeEliminationPhase(HGraph* graph)
-      : HPhase("H_Dead code elimination", graph) { }
-
-  void Run() {
-    MarkLiveInstructions();
-    RemoveDeadInstructions();
-  }
-
- private:
-  void MarkLive(HValue* instr, ZoneList<HValue*>* worklist);
-  void PrintLive(HValue* ref, HValue* instr);
-  void MarkLiveInstructions();
-  void RemoveDeadInstructions();
-};
-
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_HYDROGEN_DCE_H_