[turbofan] Use FastNewClosureStub if possible.

src/code-factory.cc

Index: src/code-factory.cc
diff --git a/src/code-factory.cc b/src/code-factory.cc
index c4063b921e66087628640f2392c74e7c37c23cb4..7277448d16dcaac165d89b083b2538e95ed2b702 100644
--- a/src/code-factory.cc
+++ b/src/code-factory.cc
@@ -159,6 +159,15 @@ Callable CodeFactory::FastCloneShallowObject(Isolate* isolate, int length) {
 
 
 // static
+Callable CodeFactory::FastNewClosure(Isolate* isolate,
+                                     LanguageMode language_mode,
+                                     FunctionKind kind) {
+  FastNewClosureStub stub(isolate, language_mode, kind);
+  return Callable(stub.GetCode(), stub.GetCallInterfaceDescriptor());
+}
+
+
+// static
 Callable CodeFactory::AllocateHeapNumber(Isolate* isolate) {
   AllocateHeapNumberStub stub(isolate);
   return Callable(stub.GetCode(), stub.GetCallInterfaceDescriptor());