When creating system threads like the async GC thread, finalizer thread, idle
thread, etc. we do so directly from C. In doing so we fail to set all the fields in
the Thread object that are visible from Java users. So in mem's recent thread
monitor applet, things like the async GC thread appear as non-daemon and
at priority 0, where such system threads should probably be all daemon and
have nonzero priorities. I've actually already fixed this...