cpp-options: -D_SDL_main_h needs to be added to the .cabal file to compile on Windows with GHC 8.0.2 (credits to <RyanGlScott> in #ghc http://ircbrowse.net/day/ghc/2017/01/28)

It looks like this is technically a problem with the hsc2hs implementation (see above irc discussion) so this isn't necessarily an issue with sdl2 itself, but if this cpp flag doesn't cause any other issues I can make a patch for it