Added a test that provokes the hypothesized (in my last checkin comment)

debug-build failure when an instance of a new-style class is resurrected
by a __del__ method -- we simply never had any code that tried this.

This is already fixed in 2.3 CVS.  In 2.2.1, it blows up via

    Fatal Python error: GC object already in linked list

I'll fix it in 2.2.1 CVS next.