[turbofan] Various cleanups.

src/compiler/js-graph.h

Index: src/compiler/js-graph.h
diff --git a/src/compiler/js-graph.h b/src/compiler/js-graph.h
index 064359423fb5f2f6e032f0b182bb7cd9c0deca96..040a745e3cfd553a7796f36846197084c46db7f2 100644
--- a/src/compiler/js-graph.h
+++ b/src/compiler/js-graph.h
@@ -115,6 +115,7 @@ class JSGraph : public ZoneObject {
   Graph* graph() { return graph_; }
   Zone* zone() { return graph()->zone(); }
   Isolate* isolate() { return zone()->isolate(); }
+  Factory* factory() { return isolate()->factory(); }
 
   void GetCachedNodes(NodeVector* nodes);
 
@@ -140,8 +141,6 @@ class JSGraph : public ZoneObject {
   Node* ImmovableHeapConstant(Handle<HeapObject> value);
   Node* NumberConstant(double value);
 
-  Factory* factory() { return isolate()->factory(); }
-
   DISALLOW_COPY_AND_ASSIGN(JSGraph);
 };