50% faster async / Promise

This makes promises & async take two ticks instead of three ticks.

See tc39/ecma262#1250
See tc39/ecma262#2770
See tc39/ecma262#2772

50% faster when measuring call overhead. Similar improvements for https:/v8/promise-performance-tests and when measuring with the following snippet:

```js
import { run, bench } from "mitata";

bench("sync", () => {});
bench("async", async () => {});

run();
```

Source/JavaScriptCore/builtins/PromiseOperations.js

@@ -175,6 +175,12 @@ function resolvePromise(promise, resolution)
  if (!@isObject(resolution))
  return @fulfillPromise(promise, resolution);
 
+ if (@isPromise(resolution)) {
+ if (resolution.constructor === @Promise || resolution.constructor === @InternalPromise) {
+ return @performPromiseThen(resolution, @undefined, @undefined, promise);
+ }
+ }
+
  var then;
  try {
  then = resolution.then;
@@ -312,6 +318,12 @@ function resolveWithoutPromise(resolution, onFulfilled, onRejected)
  return;
  }
 
+ if (@isPromise(resolution)) {
+ if (resolution.constructor === @Promise || resolution.constructor === @InternalPromise) {
+ return @performPromiseThen(resolution, onFulfilled, onRejected, @undefined);
+ }
+ }
+
  var then;
  try {
  then = resolution.then;