use `ld -r -z ibt -z shstk...` instead of magic hackery to get CET ibt
and shstk. N.B. updated yasm in f33/rawhide now has support for
.note.gnu.properties so even this will go away in the next build
signal_handler.cc, use HAVE_REENTRANT_STRSIGNAL, strsignal(3)
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>