Remove the asyncore and asynchat modules, deprecated in Python
3.6: use the asyncio module instead.
Remove the smtpd module, deprecated in Python 3.6: the aiosmtpd
module can be used instead, it is based on asyncio.
* Remove asyncore, asynchat and smtpd documentation
* Remove test_asyncore, test_asynchat and test_smtpd
* Rename Lib/asynchat.py to Lib/test/support/_asynchat.py
* Rename Lib/asyncore.py to Lib/test/support/_asyncore.py
* Rename Lib/smtpd.py to Lib/test/support/_smtpd.py
* Remove DeprecationWarning from private _asyncore, _asynchat and
_smtpd modules
* _smtpd: remove deprecated properties
The binhex module, deprecated in Python 3.9, is now removed. The
following binascii functions, deprecated in Python 3.9, are now also
removed:
* a2b_hqx(), b2a_hqx();
* rlecode_hqx(), rledecode_hqx().
The binascii.crc_hqx() function remains available.
Add frozen modules to sys.stdlib_module_names. For example, add
"_frozen_importlib" and "_frozen_importlib_external" names.
Add "list_frozen" command to Programs/_testembed.