Re: [streams] WIP: exclusive reader interface (#251)

OK, I updated to a design where closing or erroring the stream auto-releases the lock. Also, when the lock is released, `.closed`, `.ready`, and `.state` still work (by passing through to the stream).

This allows us to make `.closed` a pass-through, so that it always has the correct semantics. It also is probably nicer for authors to get the auto-release semantics.

I added the TODO'ed tests, and updated the sections of the spec that I'd already written. I'll flesh out the missing parts of the spec next.

---
Reply to this email directly or view it on GitHub:
https://github.com/whatwg/streams/pull/251#issuecomment-67907675