Clean up hash creation code to use Handle<Smi> where possible

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 1fc270c7255ceddbdae4557714de08a7562a15c1..839b73eba7f0e71e019689c0f72f6e5cb2817b63 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -3584,8 +3584,7 @@ int v8::Object::GetIdentityHash() {
   ENTER_V8(isolate);
   i::HandleScope scope(isolate);
   i::Handle<i::JSObject> self = Utils::OpenHandle(this);
-  return i::Handle<i::Smi>::cast(
-      i::JSReceiver::GetOrCreateIdentityHash(self))->value();
+  return i::JSReceiver::GetOrCreateIdentityHash(self)->value();
 }