[turbofan] Machine operators are globally shared singletons.

test/cctest/compiler/graph-builder-tester.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_CCTEST_COMPILER_GRAPH_BUILDER_TESTER_H_
 #define V8_CCTEST_COMPILER_GRAPH_BUILDER_TESTER_H_
 
 #include "src/v8.h"
 #include "test/cctest/cctest.h"
 
@@ skipping 43 matching lines @@
   Graph* graph_;
   MaybeHandle<Code> code_;
 };
 
 
 class GraphAndBuilders {
  public:
   explicit GraphAndBuilders(Zone* zone)
       : main_graph_(new (zone) Graph(zone)),
         main_common_(zone),
-        main_machine_(zone),
         main_simplified_(zone) {}
 
  protected:
   // Prefixed with main_ to avoid naiming conflicts.
   Graph* main_graph_;
   CommonOperatorBuilder main_common_;
   MachineOperatorBuilder main_machine_;
   SimplifiedOperatorBuilder main_simplified_;
 };
 
@@ skipping 24 matching lines @@
   }
   virtual ~GraphBuilderTester() {}
 
   Factory* factory() const { return isolate()->factory(); }
 };
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CCTEST_COMPILER_GRAPH_BUILDER_TESTER_H_