[turbofan] Machine operators are globally shared singletons.

src/compiler/machine-operator-reducer.cc

 // 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.
 
 #include "src/compiler/machine-operator-reducer.h"
 
 #include "src/base/bits.h"
 #include "src/compiler/generic-node-inl.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-matchers.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 MachineOperatorReducer::MachineOperatorReducer(JSGraph* jsgraph)
-    : jsgraph_(jsgraph), machine_(jsgraph->zone()) {}
+    : jsgraph_(jsgraph) {}
 
 
 MachineOperatorReducer::~MachineOperatorReducer() {}
 
 
 Node* MachineOperatorReducer::Float64Constant(volatile double value) {
   return jsgraph()->Float64Constant(value);
 }
 
 
@@ skipping 446 matching lines @@
 CommonOperatorBuilder* MachineOperatorReducer::common() const {
   return jsgraph()->common();
 }
 
 
 Graph* MachineOperatorReducer::graph() const { return jsgraph()->graph(); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8