Windows 8 SDKs complain that GetVersion() is deprecated.
We only use GetVersion like this:
(GetVersion() < 0x80000000)
which checks if the Windows version is NT based. Use a macro check_winnt()
which uses GetVersion() on older SDK versions and true otherwise.
(cherry picked from commit a4cc3c8041104896d51ae12ef7b678c31808ce52)