[Atomics.waitAsync] Fix: mark timeout task as cancelled properly

Bug: v8:10239, v8:10775
Change-Id: Ic12f9da7f8bb10f83c9e3c00f39a26412e058943
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2340904Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69257}

src/execution/futex-emulation.cc

@@ -749,12 +749,12 @@ void FutexEmulation::HandleAsyncWaiterTimeout(FutexWaitListNode* node) {
 
   base::MutexGuard lock_guard(g_mutex.Pointer());
 
+  node->timeout_task_id_ = CancelableTaskManager::kInvalidTaskId;
   if (!node->waiting_) {
     // If the Node is not waiting, it's already scheduled to have its Promise
     // resolved. Ignore the timeout.
     return;
   }
-  node->timeout_task_id_ = CancelableTaskManager::kInvalidTaskId;
   g_wait_list.Pointer()->RemoveNode(node);
   HandleScope handle_scope(node->isolate_for_async_waiters_);
   ResolveAsyncWaiterPromise(node);