[async-await] Remove call indirection in Create and Reject

Instead of exporting/importing PromiseCreate and RejectPromise and going
through them, just call the runtime function / the TF builtin on the
context directly.

BUG=v8:5639

Review-Url: https://codereview.chromium.org/2599003002
Cr-Commit-Position: refs/heads/master@{#42160}

src/js/async-await.js

@@ -13,15 +13,10 @@
 
 var AsyncFunctionNext;
 var AsyncFunctionThrow;
-var PromiseCreate;
-var PromiseNextMicrotaskID;
-var RejectPromise;
 
 utils.Import(function(from) {
   AsyncFunctionNext = from.AsyncFunctionNext;
   AsyncFunctionThrow = from.AsyncFunctionThrow;
-  PromiseCreate = from.PromiseCreate;
-  RejectPromise = from.RejectPromise;
 });
 
 var promiseAsyncStackIDSymbol =
@@ -38,7 +33,7 @@ function PromiseCastResolved(value) {
   if (%is_promise(value)) {
     return value;
   } else {
-    var promise = PromiseCreate(UNDEFINED);
+    var promise = %promise_internal_constructor(UNDEFINED);
     %promise_resolve(promise, value);
     return promise;
   }
@@ -77,7 +72,7 @@ function AsyncFunctionAwait(generator, awaited, outerPromise) {
     return;
   }
 
-  var throwawayPromise = PromiseCreate(promise);
+  var throwawayPromise = %promise_internal_constructor(promise);
 
   // The Promise will be thrown away and not handled, but it shouldn't trigger
   // unhandled reject events as its work is done
@@ -115,11 +110,11 @@ function AsyncFunctionAwaitCaught(generator, awaited, outerPromise) {
 
 // How the parser rejects promises from async/await desugaring
 function RejectPromiseNoDebugEvent(promise, reason) {
-  return RejectPromise(promise, reason, false);
+  return %PromiseReject(promise, reason, false);
 }
 
 function AsyncFunctionPromiseCreate() {
-  var promise = PromiseCreate();
+  var promise = %promise_internal_constructor(UNDEFINED);
   if (DEBUG_IS_ACTIVE) {
     // Push the Promise under construction in an async function on
     // the catch prediction stack to handle exceptions thrown before

src/js/promise.js

@@ -36,11 +36,6 @@ function PromiseCreate(parent) {
   return %promise_internal_constructor(parent);
 }
 
-// Only used by async-await.js
-function RejectPromise(promise, reason, debugEvent) {
-  %PromiseReject(promise, reason, debugEvent);
-}
-
 // Export to bindings
 function DoRejectPromise(promise, reason) {
   %PromiseReject(promise, reason, true);
@@ -174,9 +169,4 @@ utils.InstallFunctions(extrasUtils, 0, [
   "markPromiseAsHandled", MarkPromiseAsHandled
 ]);
 
-utils.Export(function(to) {
-  to.PromiseCreate = PromiseCreate;
-  to.RejectPromise = RejectPromise;
-});
-
 })