Fix WITNESS when INVARIANT_SUPPORT is defined.

This fixes tinderbox breakage from r244105.

Pointed out by: adrian
Cleanup more of the kassert_panic.

fix compile warnings on !amd64 and NULL derefs that would happen
if kassert_panic() would return.
Merge 1.127 from OpenBSD, that closes a regression from 1.125 (merged
as r242694):
  do better detection of when we have a better version of the tcp sequence
  windows than our peer.

  this resolves the last of the pfsync traffic storm issues ive been able to
  produce, and therefore makes it possible to do usable active-active
  statuful firewalls with pf.
Add pci id for the xeon hd4000 (IvyBridge server GT2)

Submitted by:	François Tigeot <ftigeot@wolfpond.org>
Obtained from:	dragonfly
MFC after:	3 days
Remove 'dangerous' instructions from the example make.conf.
Clarify when and why these might be used and that this isn't a supported
configuration.

PR:		docs/144488
Submitted by:	amdmi3
Approved by:	cperciva (implicit)
MFC after:	2 weeks
Similar to CTLFLAG_RDTUN, provide CTLFLAG_RWTUN that defines writable sysctl
that can also be modified by loader tunable.
Cleanup a few duplicate llvm libs that snuck in with the recent update.

Noticed by:	rdivacky
libc: Make various internal file descriptors close-on-exec.

These are obtained via fopen().
Add -R, an option to restart all enabled "local" services.

Discussed on:	-rc@ (in September)
MFC after:	2 months
Make Tflag and Wflag filters work for more sysctl options.

To do this move the Tflag and Wflag checks earlier in show_var() so
we bail earlier for variables not matching our query.
Handle large negative block counts correctly.

MFC after:	 2 weeks
virtio_scsi: Remove duplicated lines

These must have been accidently copied from the if statement a few
lines later. Also remove parameter name from function prototype.

Approved by:	grehan (mentor)
Implement an API to allow a hypervisor to save/restore
guest floating point state without having to know the
size of floating-point state.

Unstaticize fpurestore to allow the hypervisor to
save/restore guest state using fpusave/fpurestore
on the allocated FPU state area.

Reviewed by:	kib
Obtained from:	NetApp/bhyve
MFC after:	1 week
Add quirks for AD1984A codec and Lenovo X300 laptop.

PR:		kern/148741
MFC after:	2 weeks
Add IDs for SATA controllers on AMD Hudson-2 series chipsets.
I am not exactly sure about the naming due to lack of specs on AMD site,
but it is better to have some identification then none at all.

MFC after:	1 month
Eliminate redundant variable.
Use kern.max_pid sysctl to obtain maximum PID number instead of using local
define.

Reviewed by:	jhb
Renamed zfs trim stats removing duplicate zio_trim identifier from the name
Added description option to kstats.
Added descriptions for zio_trim kstats

PR:		kern/173113
Submitted by:	Steven Hartland
Reviewed by:	pjd
Approved by:	pjd
MFC after:	2 weeks
Add myself as a new src committer

Approved by:	pjd (mentor)
  Fix a crash in tcp_input(), that happens when mbuf has a fwd_tag on it,
but later after processing and freeing the tag, we need to jump back again
to the findpcb label. Since the fwd_tag pointer wasn't NULL we tried to
process and free the tag for second time.

Reported & tested by:	Pawel Tyll <ptyll nitronet.pl>
MFC after:		3 days