[promises] Remove one runtime call to create_resolving_functions

src/promise-utils.h

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_PROMISE_UTILS_H_
+#define V8_PROMISE_UTILS_H_
+
+#include "src/objects.h"
+
+namespace v8 {
+namespace internal {
+
+// Helper methods for Promise builtins.
+class PromiseUtils : public AllStatic {
+ public:
+  // These get and set the slots on the PromiseResolvingContext, which
+  // is used by the resolve/reject promise callbacks.
+  static JSObject* GetPromise(Handle<Context> context);
+  static Object* GetDebugEvent(Handle<Context> context);
+  static bool HasAlreadyVisited(Handle<Context> context);
+  static void SetAlreadyVisited(Handle<Context> context);
+
+  static void CreateResolvingFunctions(Isolate* isolate,
+                                       Handle<JSObject> promise,
+                                       Handle<Object> debug_event,
+                                       Handle<JSFunction>* resolve,
+                                       Handle<JSFunction>* reject);
+};
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_PROMISE_UTILS_H_