Unstage non-standard Promise functions

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 426 matching lines @@
 };
 
 // -------------------------------------------------------------------
 // Install exported functions.
 
 %AddNamedProperty(global, 'Promise', GlobalPromise, DONT_ENUM);
 %AddNamedProperty(GlobalPromise.prototype, toStringTagSymbol, "Promise",
                   DONT_ENUM | READ_ONLY);
 
 utils.InstallFunctions(GlobalPromise, DONT_ENUM, [
-  "defer", PromiseDeferred,
-  "accept", PromiseResolved,
   "reject", PromiseRejected,
   "all", PromiseAll,
   "race", PromiseRace,
   "resolve", PromiseCast
 ]);
 
 utils.InstallFunctions(GlobalPromise.prototype, DONT_ENUM, [
-  "chain", PromiseChain,
   "then", PromiseThen,
   "catch", PromiseCatch
 ]);
 
 %InstallToContext([
   "promise_catch", PromiseCatch,
   "promise_chain", PromiseChain,
   "promise_create", PromiseCreate,
   "promise_has_user_defined_reject_handler", PromiseHasUserDefinedRejectHandler,
   "promise_reject", PromiseReject,
   "promise_resolve", PromiseResolve,
   "promise_then", PromiseThen,
 ]);
 
 // This allows extras to create promises quickly without building extra
 // resolve/reject closures, and allows them to later resolve and reject any
 // promise without having to hold on to those closures forever.
 utils.InstallFunctions(extrasUtils, 0, [
   "createPromise", PromiseCreate,
   "resolvePromise", PromiseResolve,
   "rejectPromise", PromiseReject
 ]);
 
+// TODO(v8:4567): Allow experimental natives to remove function prototype
+[PromiseChain, PromiseDeferred, PromiseResolved].forEach(
+    fn => %FunctionRemovePrototype(fn));
+
+utils.Export(function(to) {
+  to.PromiseChain = PromiseChain;
+  to.PromiseDeferred = PromiseDeferred;
+  to.PromiseResolved = PromiseResolved;
+});
+
 })