swapcontext wrapper can not be implemented in C, the stack pointer saved in
the context becomes invalid when the function returns, same as setjmp,
it must be implemented in assemble language, see discussions in PR
misc/177624.
Unsynchronized TSCs on the host require special handling in bhyve:

- use clock_gettime(2) as the time base for the emulated ACPI timer instead
  of directly using rdtsc().

- don't advertise the invariant TSC capability to the guest to discourage it
  from using the TSC as its time base.

Discussed with:	jhb@ (about making 'smp_tsc' a global)
Reported by:	Dan Mack on freebsd-virtualization@
Obtained from:	NetApp
Cast to (void *)(uintptr_t) on copyout and copyin of zfs_iocparm_t.zfs_cmd

MFC after:	9 days
Fix build.
Make ctladm(8) try to load ctl.ko kernel module if needed.

Reviewed by:	ken
Remove the number of addresses restriction from sctp_connectx().
Remove unused code.
While there, do some cleanup of the code.

MFC after: 1 week
Fix a time calculation error in ctlstat_standard().

ctlstat.c:	When converting a timeval to a floating point
		number in ctlstat_standard(), cast the nanoseconds
		calculation to a long double, so we don't lose
		precision.  Without the cast, we wind up with a
		time in whole seconds only.

Sponsored by:	Spectra Logic
MFC after:	3 days
Merge branch 'master' into markj-kernel-config
Add snp(4).