Re: [whatwg/dom] Specify that AbortController#abort() be bound to AbortController instance (#981)

> > Do you find you need to "break out" with the `Promise` constructor as well?

I've personally used it quite a few times in particular for concurrency management, e.g. locks, (async) task queues, etc etc.

A typical example would be something like lock:

```js
class Deferred {
  resolve;
  reject;
  promise = new Promise((resolve, reject) => {
    this.resolve = resolve;
    this.reject = reject;
  });
}

class Lock {
  #locked = false;
  #pendingRequests = [];
  
  #release = () => {
    assert(this.#locked);
    const firstPending = this.#pendingRequests.shift();
    if (firstPending) {
      firstPending.resolve(once(this.#release));
    } else {
      this.#locked = false;
    }
  }
  
  async acquire() {
    if (this.#locked) {
      const deferred = new Deferred();
      this.#pendingRequests.push(deferred);
      return await deferred.promise;
    }
    this.#locked = true;
    return once(this.#release);
  }
}
```

---

Although I can say one place I have specifically wanted the revealing constructor pattern on `AbortSignal` is to be able to subclass `AbortSignal`, which is otherwise undoable as `AbortSignal` has to be tied to a controller (so `super()` always throws, as `new AbortSignal()` always throws). It might be doable by some awful `super` override hacks, but real subclassing would be a lot nicer.

Although I wouldn't even need the subclass (actually a parallel implementation + extra methods) if a [few](https://github.com/whatwg/dom/issues/951) [suggestions](https://github.com/whatwg/dom/issues/948) [were](https://github.com/whatwg/dom/issues/946) [all](https://github.com/whatwg/dom/issues/920) [added](https://github.com/whatwg/dom/issues/927), the only reason I have the parallel implementation is that the listed issues are basically all things I use heavily when working with `AbortSignal` so it's just too cumbersome not to have them consistently available.

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