Improve memory usage in Turbofan.

src/compiler/graph-inl.h

Index: src/compiler/graph-inl.h
diff --git a/src/compiler/graph-inl.h b/src/compiler/graph-inl.h
index 571ffb3c5b6f114d571ebf387f2235da516f271c..efebf7bcb9b866327fd861eecb43cd3b68c87fde 100644
--- a/src/compiler/graph-inl.h
+++ b/src/compiler/graph-inl.h
@@ -14,8 +14,9 @@ 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);
 }
 
 
@@ -27,8 +28,9 @@ void Graph::VisitNodeUsesFromStart(Visitor* 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);
 }
 }
 }