tst-basic3 failing

I am making some good progress on getting NPTL running on PowerPC.
However, I have run into a problem with tst-basic3.  The initial
thread segfaults after creating the 20 child threads.  It turns out
that it is doing a longjmp on an uninitialized jmp_buf.  It calls
pthread_exit, which calls __do_cancel, which calls __libc_longjmp on
self->cancelbuf.  The cancelbuf field gets initialized in
start_thread, but of course the initial thread doesn't call
start_thread.  Unfortunately most of the thread exit processing logic
seems to be in start_thread too.

Are other architectures seeing this problem?  It looks to me like it
will take some restructuring to fix.

Paul.