[turbofan] Introduce CommonOperatorReducer.

src/compiler/common-operator-reducer.h

 // Copyright 2014 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_COMPILER_LOAD_ELIMINATION_H_
-#define V8_COMPILER_LOAD_ELIMINATION_H_
+#ifndef V8_COMPILER_COMMON_OPERATOR_REDUCER_H_
+#define V8_COMPILER_COMMON_OPERATOR_REDUCER_H_
 
 #include "src/compiler/graph-reducer.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
-class LoadElimination FINAL : public Reducer {
+// Performs strength reduction on nodes that have common operators.
+class CommonOperatorReducer FINAL : public Reducer {
  public:
-  LoadElimination() {}
-  ~LoadElimination() FINAL;
+  CommonOperatorReducer() {}
+  ~CommonOperatorReducer() FINAL {}
 
   Reduction Reduce(Node* node) FINAL;
-
- private:
-  Reduction ReduceLoadField(Node* node);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_COMPILER_LOAD_ELIMINATION_H_
+#endif  // V8_COMPILER_COMMON_OPERATOR_REDUCER_H_