TIC-80 doesn't work when forced to run under Wayland

[aliceisjustplaying]

SDL2 apps run under X11/Xwayland by default. If I force TIC-80 to run under Wayland with SDL_VIDEODRIVER=wayland (which should work (?)), it launches but I see no UI whatsoever (do get audio though).

Found while working on #2657.

[nesbox]

Maybe we need to play with these options in SDL2 cmake
https://github.com/libsdl-org/SDL/blob/f070c83a6059c604cbd098680ddaee391b0a7341/CMakeLists.txt#L490

[aliceisjustplaying]

Ok, sdl-gpu breaks under Wayland, haven't gone too deep why, it's an old library the first place. if I compile TIC-80 without it, I can run it on Wayland but it does not handle scaling well (this is on a retina display with scaling set to 200%) which is the next thing I'll look into.

[aliceisjustplaying]

I do wonder how much work would it be to remove the sdl-gpu dependency and code the CRT feature without it, may look into that as well.