Build failing on non-Windows systems

SDL fails to link when building on non-Windows systems since the recent XInput changes for Windows ( https://hg.libsdl.org/SDL/rev/47fb6a7e7f68 ).

I created a bug report at https://bugzilla.libsdl.org/show_bug.cgi?id=2627 , but I figured I?d poke the powers that be here as well. :slight_smile: