Reland Create JSPromise (patchset #16 id:300001 of https://codereview.chromium.org/2536463002/ )"

src/js/async-await.js

 // 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.
 
 (function(global, utils, extrasUtils) {
 
 "use strict";
 
 %CheckIsBootstrapping();
 
 // -------------------------------------------------------------------
 // Imports
 
 var AsyncFunctionNext;
 var AsyncFunctionThrow;
 var CreateInternalPromiseCapability;
-var PerformPromiseThen;
 var PromiseCreate;
 var PromiseNextMicrotaskID;
 var RejectPromise;
 var ResolvePromise;
 
 utils.Import(function(from) {
   AsyncFunctionNext = from.AsyncFunctionNext;
   AsyncFunctionThrow = from.AsyncFunctionThrow;
   CreateInternalPromiseCapability = from.CreateInternalPromiseCapability;
-  PerformPromiseThen = from.PerformPromiseThen;
   PromiseCreate = from.PromiseCreate;
   RejectPromise = from.RejectPromise;
   ResolvePromise = from.ResolvePromise;
 });
 
 var promiseAsyncStackIDSymbol =
     utils.ImportNow("promise_async_stack_id_symbol");
 var promiseHandledBySymbol =
     utils.ImportNow("promise_handled_by_symbol");
 var promiseForwardingHandlerSymbol =
     utils.ImportNow("promise_forwarding_handler_symbol");
 var promiseHandledHintSymbol =
     utils.ImportNow("promise_handled_hint_symbol");
 var promiseHasHandlerSymbol =
     utils.ImportNow("promise_has_handler_symbol");
 
 // -------------------------------------------------------------------
 
 function PromiseCastResolved(value) {
+  // TODO(caitp): This is non spec compliant. See v8:5694.
   if (%is_promise(value)) {
     return value;
   } else {
     var promise = PromiseCreate();
     ResolvePromise(promise, value);
     return promise;
   }
 }
 
 // ES#abstract-ops-async-function-await
@@ skipping 42 matching lines @@
       // than a meaningful catch handler
       SET_PRIVATE(onRejected, promiseForwardingHandlerSymbol, true);
     }
 
     // Mark the dependency to outerPromise in case the throwaway Promise is
     // found on the Promise stack
     SET_PRIVATE(throwawayCapability.promise, promiseHandledBySymbol,
                 outerPromise);
   }
 
-  PerformPromiseThen(promise, onFulfilled, onRejected, throwawayCapability);
+  %perform_promise_then(promise, onFulfilled, onRejected, throwawayCapability);
 }
 
 // Called by the parser from the desugaring of 'await' when catch
 // prediction indicates no locally surrounding catch block
 function AsyncFunctionAwaitUncaught(generator, awaited, outerPromise) {
   AsyncFunctionAwait(generator, awaited, outerPromise);
 }
 
 // Called by the parser from the desugaring of 'await' when catch
 // prediction indicates that there is a locally surrounding catch block
@@ skipping 43 matching lines @@
 
 %InstallToContext([
   "async_function_await_caught", AsyncFunctionAwaitCaught,
   "async_function_await_uncaught", AsyncFunctionAwaitUncaught,
   "reject_promise_no_debug_event", RejectPromiseNoDebugEvent,
   "async_function_promise_create", AsyncFunctionPromiseCreate,
   "async_function_promise_release", AsyncFunctionPromiseRelease,
 ]);
 
 })