or other similar work. This is not quite the same as atexit() on POSIX as
the function is *not* called if the plugin exits by returning from
plugin_start; only if exit() is called. No code overhead if it's not used.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24189 a1c6a512-1295-4272-9138-f99709370657