Add support for Simple Direct Layer (media library)

Packages describing “sdl” as local USE flag

Package “sdl” Flag Description
media-libs/libde265 Enable video output of dec265 example program with media-libs/libsdl
media-video/mpv Enable media-libs/libsdl2 based video and audio outputs (Note: these outputs exist for compatibility reasons only, avoid if possible)
app-emulation/wine-vanilla Add support for gamepad detection using SDL
app-emulation/wine-staging Add support for gamepad detection using SDL
x11-libs/wxGTK Use Simple Directmedia Layer (media-libs/libsdl) for audio.
games-emulation/pcsxr Use SDL sound backend (other parts of SDL are used unconditionally)
app-emulation/qemu Enable the SDL-based console

All packages providing a “sdl” USE flag (72)