Reuse the attach1's test body for race1.
Add a new test race1:
Assert that await_zombie() in attach1 always finds a single
process and no other error is reported
race1 requires HAVE_PID in wait(2)-like function.
This test is executed in a loop for 5 seconds (16k iterations on Intel i7).
A buggy kernel was asserting an error within this timeframe almost always.
The bug in the kernel is now gone and this test is expected to pass
correctly.
Sponsored by <The NetBSD Foundation>
a9dda15d6e