In the PerformPromise{All, Race, AllSettled} operations, the resolve
property of the constructor is looked up only once.
In the implementation, for the fast path, where the constructor's
resolve property is untainted, the resolve function is set to undefined.
Since undefined can't be a valid value for the resolve function,
we can switch on it (in CallResolve) to directly call the PromiseResolve
builtin. If the resolve property is tainted, we do an observable property
lookup, save this value, and call this property later (in CallResolve).
I ran this CL against the test262 tests locally and they all pass:
https://github.com/tc39/test262/pull/2131
Spec:
- https://github.com/tc39/ecma262/pull/1506
- https://github.com/tc39/proposal-promise-allSettled/pull/40
Bug: v8:9152
Change-Id: Icb36a90b5a244a67a729611c7b3315d2c29de6e9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1574705
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60957}
