Untokenize: An logically incorrect assert tested user input validity.
Replace it with correct logic that raises ValueError for bad input.
Issues #8478 and #12691 reported the incorrect logic.
Add an Untokenize test case and an initial test method.
Untokenize, bad assert: Merge with 3.3
whitespace
Merge with 3.3
Issue #20655: Fix test_asyncio, run also subprocess tests. Patch written by
Vajrasky Kok.
Issue #20667: test_asyncio: Skip KqueueEventLoopTests.test_read_pty_output() on
OpenBSD older than 5.5
Close #20656: Fix select.select() on OpenBSD 64-bit
Issue #8478: Untokenizer.compat now processes first token from iterator input.
Patch based on lines from Georg Brandl, Eric Snow, and Gareth Rees.
Merge with 3.3