Adapt timers to async iterables by cooling

[erights]

Stacked on #3945

Proposed as an alternative to #3854

Hi @michaelfig it turns out there already was a makeNotifierFromAsyncIterable adaptor, which sounds like it was the remaining piece we needed. I believe I wrote it long ago. However, armed with your distinction, I saw that it was hot. I rewrote it to be a coldness-preserving adaptor and then used it to make the timer repair we talked about.

[erights]

Note to reviewers:

Aside from this @ts-check, all the rest of the changes to this file are only whitespace. (Too bad GitHub's "Hide whitespace changes" doesn't really.)

[michaelfig]

Aside from this @ts-check, all the rest of the changes to this file are only whitespace. (Too bad GitHub's "Hide whitespace changes" doesn't really.)

Ah, I see why. The whitespace changes also inserted * in various places, which defeats Github's algorithm.

[michaelfig]

Wow, this is really beautiful!

I love how you've factored things, and it's a great example of what I need in order to cool the vat-bank.js balance notifiers.

And I tested that it even works, too!

[michaelfig]

Aside from this @ts-check, all the rest of the changes to this file are only whitespace. (Too bad GitHub's "Hide whitespace changes" doesn't really.)

Ah, I see why. The whitespace changes also inserted * in various places, which defeats Github's algorithm.