sdl12-compat's SDL_stdinc.h includes <stddef.h> if HAVE_STDDEF_H is defined, but until now there was nothing that would have defined that macro. In classic SDL 1.2, SDL_stdinc.h historically included this, and some games (such as Debian package 'berusky') rely on it.
stddef.h is required by ISO C89, and is unconditionally included in the headers of some widely portable libraries like libdbus, so it seems safe to assume that all platforms have it (including Windows) unless we hear otherwise.
sdl12-compat's SDL_stdinc.h includes
<stddef.h>ifHAVE_STDDEF_His defined, but until now there was nothing that would have defined that macro. In classic SDL 1.2, SDL_stdinc.h historically included this, and some games (such as Debian package 'berusky') rely on it.stddef.h is required by ISO C89, and is unconditionally included in the headers of some widely portable libraries like libdbus, so it seems safe to assume that all platforms have it (including Windows) unless we hear otherwise.
Resolves: https://github.com/libsdl-org/sdl12-compat/issues/297