GetStdHandle is unavailable outside of the desktop API subset.
This didn't use to be a problem with earlier WinSDKs, as kbhit also
used to be available only for desktop apps, and this whole section is
wrapped in #if HAVE_KBHIT. With newer WinSDKs, kbhit() is available also
for non-desktop apps, while GetStdHandle still isn't.
Signed-off-by: Martin Storsjö <martin@martin.st>