Add isPromise V8 extras util

src/js/prologue.js

 // Copyright 2015 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 150 matching lines @@
 utils.InstallFunctions = InstallFunctions;
 utils.InstallGetter = InstallGetter;
 utils.OverrideFunction = OverrideFunction;
 utils.SetUpLockedPrototype = SetUpLockedPrototype;
 utils.PostNatives = PostNatives;
 
 %ToFastProperties(utils);
 
 // -----------------------------------------------------------------------
 
-%OptimizeObjectForAddingMultipleProperties(extrasUtils, 7);
+%OptimizeObjectForAddingMultipleProperties(extrasUtils, 11);

[Dan Ehrenberg, 2017/04/06 13:01:30]

Nit: If you switch to InstallFunctions or similar logic, you won't risk this
getting out of sync. But no need to block this patch on that cleanup--anyway,
the utils object uses the same pattern.

 
 extrasUtils.logStackTrace = function logStackTrace() {
   %DebugTrace();
 };
 
 extrasUtils.log = function log() {
   let message = '';
   for (const arg of arguments) {
     message += arg;
   }
@@ skipping 42 matching lines @@
 
 // [[PromiseState]] values (for extrasUtils.promiseState())
 // These values should be kept in sync with PromiseStatus in globals.h
 extrasUtils.kPROMISE_PENDING = 0;
 extrasUtils.kPROMISE_FULFILLED = 1;
 extrasUtils.kPROMISE_REJECTED = 2;
 
 %ToFastProperties(extrasUtils);
 
 })