[turbofan] Machine operators are globally shared singletons.

src/compiler/js-typed-lowering.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_OPERATOR_REDUCERS_H_
 #define V8_COMPILER_OPERATOR_REDUCERS_H_
 
 #include "src/compiler/graph-reducer.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node.h"
 #include "src/compiler/simplified-operator.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Lowers JS-level operators to simplified operators based on types.
 class JSTypedLowering FINAL : public Reducer {
  public:
   explicit JSTypedLowering(JSGraph* jsgraph)
-      : jsgraph_(jsgraph),
-        simplified_(jsgraph->zone()),
-        machine_(jsgraph->zone()) {}
+      : jsgraph_(jsgraph), simplified_(jsgraph->zone()) {}
   virtual ~JSTypedLowering();
 
   virtual Reduction Reduce(Node* node) OVERRIDE;
 
   JSGraph* jsgraph() { return jsgraph_; }
   Graph* graph() { return jsgraph_->graph(); }
 
  private:
   friend class JSBinopReduction;
 
@@ skipping 22 matching lines @@
   JSGraph* jsgraph_;
   SimplifiedOperatorBuilder simplified_;
   MachineOperatorBuilder machine_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_OPERATOR_REDUCERS_H_