[crankshaft] Delete unused Hydrogen-BCH code

src/crankshaft/hydrogen-bch.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_CRANKSHAFT_HYDROGEN_BCH_H_
-#define V8_CRANKSHAFT_HYDROGEN_BCH_H_
-
-#include "src/crankshaft/hydrogen.h"
-
-namespace v8 {
-namespace internal {
-
-
-class HBoundsCheckHoistingPhase : public HPhase {
- public:
-  explicit HBoundsCheckHoistingPhase(HGraph* graph)
-      : HPhase("H_Bounds checks hoisting", graph) { }
-
-  void Run() {
-    HoistRedundantBoundsChecks();
-  }
-
- private:
-  void HoistRedundantBoundsChecks();
-
-  DISALLOW_COPY_AND_ASSIGN(HBoundsCheckHoistingPhase);
-};
-
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_CRANKSHAFT_HYDROGEN_BCE_H_