[promises] Avoid creating resolving functions in Promise.resolve

src/js/promise.js

 // Copyright 2012 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.
 
 (function(global, utils, extrasUtils) {
 
 "use strict";
 
 %CheckIsBootstrapping();
 
@@ skipping 431 matching lines @@
 // Combinators.
 
 // ES#sec-promise.resolve
 // Promise.resolve ( x )
 function PromiseResolve(x) {
   if (!IS_RECEIVER(this)) {
     throw MakeTypeError(kCalledOnNonObject, PromiseResolve);
   }
   if (IsPromise(x) && x.constructor === this) return x;
 
+  // Avoid creating resolving functions.
+  if (this === GlobalPromise) {
+    var promise = PromiseInit(new GlobalPromise(promiseRawSymbol));
+    var resolveResult = ResolvePromise(promise, x);
+    return promise;
+  }
+
   var promiseCapability = NewPromiseCapability(this);
   var resolveResult = %_Call(promiseCapability.resolve, UNDEFINED, x);
   return promiseCapability.promise;
 }
 
 // ES#sec-promise.all
 // Promise.all ( iterable )
 function PromiseAll(iterable) {
   if (!IS_RECEIVER(this)) {
     throw MakeTypeError(kCalledOnNonObject, "Promise.all");
@@ skipping 156 matching lines @@
   to.PromiseChain = PromiseChain;
   to.PromiseDefer = PromiseDefer;
   to.PromiseAccept = PromiseAccept;
 
   to.PromiseCreateRejected = PromiseCreateRejected;
   to.PromiseCreateResolved = PromiseCreateResolved;
   to.PromiseThen = PromiseThen;
 });
 
 })