[turbofan] Initial import of SimplifiedOperatorReducer.

src/compiler/graph-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_GRAPH_REDUCER_H_
 #define V8_COMPILER_GRAPH_REDUCER_H_
 
 #include <list>
 
 #include "src/zone-allocator.h"
@@ skipping 20 matching lines @@
 };
 
 
 // A reducer can reduce or simplify a given node based on its operator and
 // inputs. This class functions as an extension point for the graph reducer for
 // language-specific reductions (e.g. reduction based on types or constant
 // folding of low-level operators) can be integrated into the graph reduction
 // phase.
 class Reducer {
  public:
+  Reducer() {}
   virtual ~Reducer() {}
 
   // Try to reduce a node if possible.
   virtual Reduction Reduce(Node* node) = 0;
 
   // Helper functions for subclasses to produce reductions for a node.
   static Reduction NoChange() { return Reduction(); }
   static Reduction Replace(Node* node) { return Reduction(node); }
   static Reduction Changed(Node* node) { return Reduction(node); }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(Reducer);
 };
 
 
 // Performs an iterative reduction of a node graph.
 class GraphReducer V8_FINAL {
  public:
   explicit GraphReducer(Graph* graph);
 
   Graph* graph() const { return graph_; }
 
   void AddReducer(Reducer* reducer) { reducers_.push_back(reducer); }
 
   // Reduce a single node.
   void ReduceNode(Node* node);
   // Reduce the whole graph.
   void ReduceGraph();
 
  private:
   typedef std::list<Reducer*, zone_allocator<Reducer*> > Reducers;
 
   Graph* graph_;
   Reducers reducers_;
+
+  DISALLOW_COPY_AND_ASSIGN(GraphReducer);
 };
-}
-}
-}  // namespace v8::internal::compiler
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_COMPILER_GRAPH_REDUCER_H_