> FindFirst/NextFileA will also do some other interesting conversions,
> such as the best-fit conversion (which the "mbcs" code doesn't do
> (anymore?)).

If we choose to keep this behaviour, I will have to revert my commit on mbcs 
codec to be consistent with os.listdir(). Or at least patch 
PyUnicode_EncodeFSDefault and os.fsencode() (use replace error handler) and 
PyUnicode_DecodeFSDefault and os.fsdecode() (use igrore error handler).