[promises] Move PromiseHasUserDefinedRejectHandler to c++

src/runtime/runtime-promise.cc

Index: src/runtime/runtime-promise.cc
diff --git a/src/runtime/runtime-promise.cc b/src/runtime/runtime-promise.cc
index d8e3dcaad3ee1fb21eab756a55a66d3e938739dd..3ded2e3cff88110d2e4f3fc0aed99a119ca58ea4 100644
--- a/src/runtime/runtime-promise.cc
+++ b/src/runtime/runtime-promise.cc
@@ -287,6 +287,15 @@ RUNTIME_FUNCTION(Runtime_PromiseMarkAsHandled) {
   return isolate->heap()->undefined_value();
 }
 
+RUNTIME_FUNCTION(Runtime_PromiseMarkHandledHint) {
+  HandleScope scope(isolate);

[Yang, 2016/12/23 08:40:08]

No need to create a handle scope here. And above as well. Turn that into a
SealHandleScope please.

[gsathya, 2016/12/23 17:59:44]

Done.

+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSPromise, promise, 0);
+
+  promise->set_handled_hint(true);
+  return isolate->heap()->undefined_value();
+}
+
 RUNTIME_FUNCTION(Runtime_PromiseHookInit) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());