Update Promise PJs

[jridgewell]

Fixes #10730.

A very interesting bug where promise adoption (an inner promise being
returned in side a #then block causes the outer to adopt the inner)
would not update the state of the outer promise if the inner was still
pending.

This only appeared when:

1. The outer promise was stored, and not used as a larger chain.
2. The inner promise was pending.
3. The outer promise has a #then block after the inner promise
   resolved.

var inner = new Promise(res => setTimeout(res, 0));
var outer = new Promise(res => res(inner));

// wait till after inner resolves
outer.then(() => {
  // I'll never be called. Whooops.
});

[dreamofabear]

Thanks for the super quick fix!