Test StringLengthStub generation via TurboFan.

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index 2ae4ba7085e37e1a10b3c0a73acd623034324ac5..09e55a9bffc2661fd49a37351785bf885aa27217 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -1009,15 +1009,25 @@ class LoadConstantStub : public HandlerStub {
 };
 
 
-class StringLengthStub: public HandlerStub {
+class StringLengthStub : public CodeStub {
  public:
-  explicit StringLengthStub(Isolate* isolate) : HandlerStub(isolate) {}
+  explicit StringLengthStub(Isolate* isolate) : CodeStub(isolate) {}
 
- protected:
-  Code::Kind kind() const OVERRIDE { return Code::LOAD_IC; }
-  Code::StubType GetStubType() const OVERRIDE { return Code::FAST; }
+  StringLengthStub(uint32_t key, Isolate* isolate) : CodeStub(key, isolate) {}
+
+  CallInterfaceDescriptor GetCallInterfaceDescriptor() OVERRIDE {
+    return LoadDescriptor(isolate());
+  };
 
-  DEFINE_HANDLER_CODE_STUB(StringLength, HandlerStub);
+  Handle<Code> GenerateCode() OVERRIDE;
+
+  Major MajorKey() const OVERRIDE { return StringLength; };
+  Code::Kind GetCodeKind() const OVERRIDE { return Code::HANDLER; }
+  InlineCacheState GetICState() const OVERRIDE { return MONOMORPHIC; }
+  ExtraICState GetExtraICState() const OVERRIDE { return Code::LOAD_IC; }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(StringLengthStub);
 };