convert a trap that ends up in 'we_re_toast' from a boot(RB_HALT) into a real panic.  this brings amd64 inline with all of the other arches.
convert a trap that ends up in 'we_re_toast' from a boot(RB_HALT) into a
real panic.  this brings amd64 inline with all of the other arches.

OK kettenis@, mikeb@, krw@, guenther@, thib@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars