Optimize the typeof operator.

src/code-stubs.cc

Index: src/code-stubs.cc
diff --git a/src/code-stubs.cc b/src/code-stubs.cc
index 46d8342c50a8b2545a231740f920e27ef445753c..21d11a93d053210cbaea3fe80833f4783b855848 100644
--- a/src/code-stubs.cc
+++ b/src/code-stubs.cc
@@ -633,6 +633,9 @@ void FastNewClosureStub::InitializeDescriptor(CodeStubDescriptor* descriptor) {
 void FastNewContextStub::InitializeDescriptor(CodeStubDescriptor* d) {}
 
 
+void TypeofStub::InitializeDescriptor(CodeStubDescriptor* descriptor) {}
+
+
 void NumberToStringStub::InitializeDescriptor(CodeStubDescriptor* descriptor) {
   NumberToStringDescriptor call_descriptor(isolate());
   descriptor->Initialize(
@@ -722,6 +725,12 @@ void GrowArrayElementsStub::InitializeDescriptor(
 }
 
 
+void TypeofStub::GenerateAheadOfTime(Isolate* isolate) {
+  TypeofStub stub(isolate);
+  stub.GetCode();
+}
+
+
 void CreateAllocationSiteStub::GenerateAheadOfTime(Isolate* isolate) {
   CreateAllocationSiteStub stub(isolate);
   stub.GetCode();