Make distutils error messages more helpful (#11599).

When running external programs such as a C compiler and getting an
error code, distutils only prints the program name.  With this change,
one can get the full command line by setting the DISTUTILS_DEBUG
environment variable.

This should have no compatibility issues, unless there are tools
that depend on the exact format of distutils debug messages.
Close #20787: asyncio doc: fix typo. Patch written by akira.
Close #20889: asyncio doc: Document acquire(), locked() and release() method of
Condition
asyncio doc: functions are coroutine, they don't return a coroutine

It's not exact, but easier to understand.
Merge 3.3 (#11599)
Merge heads