Pull in r211435 from upstream llvm trunk (by Benjamin Kramer):

  Legalizer: Add support for splitting insert_subvectors.

  We handle this by spilling the whole thing to the stack and doing the
  insertion as a store.

  PR19492. This happens in real code because the vectorizer creates
  v2i128 when AVX is enabled.

This fixes a "fatal error: error in backend: Do not know how to split
the result of this operator!" message encountered during compilation of
the net-p2p/libtorrent-rasterbar port.

Reported by:	Evgeniy <iron@mail.ua>
MFC after:	3 days
Add the llvm patch for r267704.
Allow creation of SDT probes from a module in which no providers are
defined. This ensures that the sdt:zfs:: probes appear despite the fact
the sdt provider is defined in the kernel rather than in zfs.ko.

Reported by:	hiren
Tested by:	hiren
MFC after:	2 weeks
do_dup: plug redundant adjustment of fd_lastfile

By that time it was already set by fdalloc, or was there in the first place
if fd is replaced.

MFC after:	1 week
fd: replace fd_nfiles with fd_lastfile where appropriate

fd_lastfile is guaranteed to be the biggest open fd, so when the intent
is to iterate over active fds or lookup one, there is no point in looking
beyond that limit.

Few places are left unpatched for now.

MFC after:	1 week
Add note on SYSCTL VARIABLES.
add support for MosChip MCS9922...  This is found on an ExpressCard..

tested to work w/ cu talking to itself (the two ports connected via
null modem cable)...
convert to using pidfile...  This prevents multiple wpa_supplicants
running at the same time causing problems w/ wifi not working..

the patch will be submitted upstream...  The next step if someone wants
to push it upstream is to break os_unix.c up so that all these other
utilities don't need libutil..

Reviewed by:	rpaulo
Permit changing cpu mask for cpu set 1 in presence of drivers
binding their threads to particular CPU.

Changing ithread cpu mask is now performed by special cpuset_setithread().
It creates additional cpuset root group on first bind invocation.

No objection:	jhb
Tested by:	hiren
MFC after:	2 weeks
Sponsored by:	Yandex LLC
Remove the incomplete Tegra 2 code, nobody was maintaining it. The AC100
never booted to single user mode.

It can be brought back if someone is willing to get it into a stable state
and maintain it.