- Make !KDB config buildable.
- Simplify interface to nmi_handle_intr() by evaluating panic_on_nmi
in one place, namely nmi_call_kdb(). This allows to remove do_panic
argument from the functions, and to remove i386/amd64 duplication of
the variable and sysctl definitions. Note that now NMI causes
panic(9) instead of trap_fatal() reporting and then panic(9),
consistently for NMIs delivered while CPU operated in ring 0 and 3.
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks