[turbofan] Remove locally constructed simplified builders.

src/compiler/js-type-feedback-lowering.cc

 // Copyright 2015 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/js-type-feedback-lowering.h"
 
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-properties.h"
 #include "src/objects-inl.h"  // TODO(mstarzinger): Temporary cycle breaker!
 #include "src/type-feedback-vector.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 JSTypeFeedbackLowering::JSTypeFeedbackLowering(Editor* editor, Flags flags,
                                                JSGraph* jsgraph)
-    : AdvancedReducer(editor),
-      flags_(flags),
-      jsgraph_(jsgraph),
-      simplified_(graph()->zone()) {}
+    : AdvancedReducer(editor), flags_(flags), jsgraph_(jsgraph) {}
 
 
 Reduction JSTypeFeedbackLowering::Reduce(Node* node) {
   switch (node->opcode()) {
     case IrOpcode::kJSLoadNamed:
       return ReduceJSLoadNamed(node);
     default:
       break;
   }
   return NoChange();
@@ skipping 74 matching lines @@
 
 Isolate* JSTypeFeedbackLowering::isolate() const {
   return jsgraph()->isolate();
 }
 
 
 MachineOperatorBuilder* JSTypeFeedbackLowering::machine() const {
   return jsgraph()->machine();
 }
 
+
+SimplifiedOperatorBuilder* JSTypeFeedbackLowering::simplified() const {
+  return jsgraph()->simplified();
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8