Pull up following revision(s) (requested by pgoyette in ticket #1980):
sys/kern/kern_sig.c: revision 1.321
When delivering a signal, it's possible that the process's state in
p_stat is SACTIVE yet p_sflag is PS_STOPPING (while waiting for other
lwp's to stop).  In that case, we don't want to adjust the parent's
p_nstopchild count.
Found by Robert Elz.

(snj)