[turbofan] Machine operators are globally shared singletons.

src/compiler/ast-graph-builder.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/ast-graph-builder.h"
 
 #include "src/compiler.h"
 #include "src/compiler/control-builders.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node-properties.h"
@@ skipping 1906 matching lines @@
       return NewNode(op, value, current_context(), name, strict);
     }
   }
   UNREACHABLE();
   return NULL;
 }
 
 
 Node* AstGraphBuilder::BuildLoadObjectField(Node* object, int offset) {
   // TODO(sigurds) Use simplified load here once it is ready.
-  MachineOperatorBuilder machine(zone());
+  MachineOperatorBuilder machine;
   Node* field_load = NewNode(machine.Load(kMachAnyTagged), object,
                              jsgraph_->Int32Constant(offset - kHeapObjectTag));
   return field_load;
 }
 
 
 Node* AstGraphBuilder::BuildLoadBuiltinsObject() {
   Node* global = BuildLoadGlobalObject();
   Node* builtins =
       BuildLoadObjectField(global, JSGlobalObject::kBuiltinsOffset);
@@ skipping 75 matching lines @@
     DCHECK(node->InputAt(frame_state_index)->op()->opcode() == IrOpcode::kDead);
 
     Node* frame_state_node = environment()->Checkpoint(ast_id, combine);
     node->ReplaceInput(frame_state_index, frame_state_node);
   }
 }
 
 }
 }
 }  // namespace v8::internal::compiler