Fix compilater warnings on Windows 64-bit
Close #18109: os.uname() now decodes fields from the locale encoding, and
socket.gethostname() now decodes the hostname from the locale encoding, instead
of using the UTF-8 encoding in strict mode.
(Merge 3.3) Close #18109: os.uname() now decodes fields from the locale
encoding, and socket.gethostname() now decodes the hostname from the locale
encoding, instead of using the UTF-8 encoding in strict mode.