SDL_KillThread broken on OS X

Yes, I’ve seen that says “use
something else”.

But I’m working with a project that is using SDL_KillThread().
SDL_SYS_KillThread says:
#ifdef FreeBSD
#warning For some reason, this doesnt actually kill a thread - FreeBSD

Apparently this is the case on OS X as well, except the warning wasn’t
printed. Even if it were, people tend to use prebuilt packages.

So anyways, SDL_KillThread goes nowhere:
SDL_WaitThread(thread, NULL);
… spin forever waiting for thread to die.

If KillThread is such a bad idea and so non-portable, perhaps it could
be taken out to remove the temptation?