Improve memory usage in Turbofan.

src/compiler/graph-inl.h

 // Copyright 2013 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_GRAPH_INL_H_
 #define V8_COMPILER_GRAPH_INL_H_
 
 #include "src/compiler/generic-algorithm-inl.h"
 #include "src/compiler/graph.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 template <class Visitor>
 void Graph::VisitNodeUsesFrom(Node* node, Visitor* visitor) {
+  Zone tmp_zone(zone()->isolate());
   GenericGraphVisit::Visit<Visitor, NodeUseIterationTraits<Node> >(
-      this, zone(), node, visitor);
+      this, &tmp_zone, node, visitor);
 }
 
 
 template <class Visitor>
 void Graph::VisitNodeUsesFromStart(Visitor* visitor) {
   VisitNodeUsesFrom(start(), visitor);
 }
 
 
 template <class Visitor>
 void Graph::VisitNodeInputsFromEnd(Visitor* visitor) {
+  Zone tmp_zone(zone()->isolate());
   GenericGraphVisit::Visit<Visitor, NodeInputIterationTraits<Node> >(
-      this, zone(), end(), visitor);
+      this, &tmp_zone, end(), visitor);
 }
 }
 }
 }  // namespace v8::internal::compiler
 
 #endif  // V8_COMPILER_GRAPH_INL_H_