What's the objection to clearing possibly-contaminated structures when a 
   program signifies its done with a privileged resource?

the objection is that for 99% or more of the cases this is
*NOT* necessary.

also, you're trying to fix the effect rather than the cause.



regardless:  until just now, netbsd allowed a process that
was set[gu]id to dump core _if_ it no longer was.  i've
fixed this (just check for SUGID in coredump()).