[promises] Remove IsPromise

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 IsPromise;
 var CreateInternalPromiseCapability;
 var PerformPromiseThen;
 var PromiseCreate;
 var PromiseNextMicrotaskID;
 var RejectPromise;
 var ResolvePromise;
 
 utils.Import(function(from) {
   AsyncFunctionNext = from.AsyncFunctionNext;
   AsyncFunctionThrow = from.AsyncFunctionThrow;
-  IsPromise = from.IsPromise;
   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) {
-  if (IsPromise(value)) {
+  if (%is_promise(value)) {
     return value;
   } else {
     var promise = PromiseCreate();
     ResolvePromise(promise, value);
     return promise;
   }
 }
 
 // ES#abstract-ops-async-function-await
 // AsyncFunctionAwait ( value )
@@ skipping 29 matching lines @@
   }
 
   // Just forwarding the exception, so no debugEvent for throwawayCapability.
   var throwawayCapability = CreateInternalPromiseCapability();
 
   // The Promise will be thrown away and not handled, but it shouldn't trigger
   // unhandled reject events as its work is done
   SET_PRIVATE(throwawayCapability.promise, promiseHasHandlerSymbol, true);
 
   if (DEBUG_IS_ACTIVE) {
-    if (IsPromise(awaited)) {
+    if (%is_promise(awaited)) {
       // Mark the reject handler callback to be a forwarding edge, rather
       // 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);
 }
 
 // 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
 function AsyncFunctionAwaitCaught(generator, awaited, outerPromise) {
-  if (DEBUG_IS_ACTIVE && IsPromise(awaited)) {
+  if (DEBUG_IS_ACTIVE && %is_promise(awaited)) {
     SET_PRIVATE(awaited, promiseHandledHintSymbol, true);
   }
   AsyncFunctionAwait(generator, awaited, outerPromise);
 }
 
 // How the parser rejects promises from async/await desugaring
 function RejectPromiseNoDebugEvent(promise, reason) {
   return RejectPromise(promise, reason, false);
 }
 
@@ skipping 31 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,
 ]);
 
 })