[promises] port NewPromiseCapability to TF

src/js/async-await.js

Index: src/js/async-await.js
diff --git a/src/js/async-await.js b/src/js/async-await.js
index 5c9c4b5ceba4931aded31ef3d98ac27502415718..c7979e4b92172aea676f6ce92736f304519f9b92 100644
--- a/src/js/async-await.js
+++ b/src/js/async-await.js
@@ -13,7 +13,6 @@
 
 var AsyncFunctionNext;
 var AsyncFunctionThrow;
-var CreateInternalPromiseCapability;
 var PromiseCreate;
 var PromiseNextMicrotaskID;
 var RejectPromise;
@@ -21,7 +20,6 @@ var RejectPromise;
 utils.Import(function(from) {
   AsyncFunctionNext = from.AsyncFunctionNext;
   AsyncFunctionThrow = from.AsyncFunctionThrow;
-  CreateInternalPromiseCapability = from.CreateInternalPromiseCapability;
   PromiseCreate = from.PromiseCreate;
   RejectPromise = from.RejectPromise;
 });
@@ -82,7 +80,7 @@ function AsyncFunctionAwait(generator, awaited, outerPromise) {
   }
 
   // Just forwarding the exception, so no debugEvent for throwawayCapability.
-  var throwawayCapability = CreateInternalPromiseCapability(promise);
+  var throwawayCapability = %new_internal_promise_capability(promise);
 
   // The Promise will be thrown away and not handled, but it shouldn't trigger
   // unhandled reject events as its work is done