Bug 79362 - Debug info is lost for .so files when they are dlclose'd. Followup fix...

Bug 79362 - Debug info is lost for .so files when they are dlclose'd.  Followup fix to avoid assertion failure when dlopening an object that has previously been dlclosed.

As reported by Matthias Schwarzott <zzam@gentoo.org>.  Testcase patch from him.  The fix is
for check_CFSI_related_invariants() to avoid checking for overlaps against DebugInfos that are
in 'archived' status, since -- if a previously dlopened-and-then-dlclosed object is later
re-dlopened -- this may cause an overlap between the active and archived DebugInfos, which
is of no consequence.  If the kernel maps the object to the same VMA the second time around
then there will *certainly* be an overlap.