Fix KASSERT typo.
Fix a couple bugs. Make the mprotect exec hardening per-jail.
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/master
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/segvguard