This switches the main pyrepl event loop to always be non-blocking so that it
can listen to incoming interruptions from other threads.
This also resolves invalid display of exceptions from other threads
(gh-123178).
This also fixes freezes with pasting and an active input hook.
This makes the asyncio REPL (`python -m asyncio`) more usable
and similar to the regular REPL.
This exposes register_readline() as a top-level function in site.py,
but it's intentionally undocumented.
Co-authored-by: Carol Willing <carolcode@willingconsulting.com>
Co-authored-by: Itamar Oren <itamarost@gmail.com>
Bartosz Sławecki