UTF-8/surrogateescape, instead of the locale encoding (which may be ASCII if no
locale environment variable is set), to avoid inconsistencies with
os.fsencode() and os.fsdecode() functions which are already using
UTF-8/surrogateescape.
* PyUnicode_DecodeLocaleAndSize() and PyUnicode_DecodeLocale() decode a string
from the current locale encoding
* _Py_char2wchar() writes an "error code" in the size argument to indicate
if the function failed because of memory allocation failure or because of a
decoding error. The function doesn't write the error message directly to
stderr.
* Fix time.strftime() (if wcsftime() is missing): decode strftime() result
from the current locale encoding, not from the filesystem encoding.
_Py_char2wchar() callers usually need the result size in characters. Since it's
trivial to compute it in _Py_char2wchar() (O(1) whereas wcslen() is O(n)), add
an option to get it.
* Don't define _Py_wstat() on Windows, Windows has its own _wstat() function
with a different API (the stat buffer has another type)
* Include windows.h
* _Py_fopen() and _Py_stat() come from Python/import.c
* (_Py)_wrealpath() comes from Python/sysmodule.c
* _Py_char2wchar(), _Py_wchar2char() and _Py_wfopen() come from Modules/main.c
* (_Py)_wstat(), (_Py)_wgetcwd(), _Py_wreadlink() come from Modules/getpath.c