privsep lost sometime between 3.5p1 and 3.7.1p1?

[Liudvikas Bukys]

I haven't recompiled since 3.5p1.
I compile --with-privsep-user=nobody

* I observe that none of my processes is uid "nobody".

In addition, previously I had to disable privsep on either AIX or OSF1
(I forget which), this time it just worked.  I was thinking it was
because Progress Had Been Made.  Now, observing so many root processes,
I think it's because privsep is not actually in effect.

* Did a default change, or is there a bug in the code?  More later.