Optimize the typeof operator.

src/code-factory.cc

Index: src/code-factory.cc
diff --git a/src/code-factory.cc b/src/code-factory.cc
index 7277448d16dcaac165d89b083b2538e95ed2b702..30448d87338bc3d635cd55b9134f3d8381caba8d 100644
--- a/src/code-factory.cc
+++ b/src/code-factory.cc
@@ -144,6 +144,13 @@ Callable CodeFactory::StringAdd(Isolate* isolate, StringAddFlags flags,
 
 
 // static
+Callable CodeFactory::Typeof(Isolate* isolate) {
+  TypeofStub stub(isolate);
+  return Callable(stub.GetCode(), stub.GetCallInterfaceDescriptor());
+}
+
+
+// static
 Callable CodeFactory::FastCloneShallowArray(Isolate* isolate) {
   // TODO(mstarzinger): Thread through AllocationSiteMode at some point.
   FastCloneShallowArrayStub stub(isolate, DONT_TRACK_ALLOCATION_SITE);