Add very simple virtio_random(4) driver to harvest entropy from host

Reviewed by:	markm (random bits only)
Replace LIBGCC by LIBCOMPILER_RT.

We now use libcompiler_rt on all platforms now. Instead of referring
directly to -lgcc and LIBGCC, use -lcompiler_rt and LIBCOMPILER_RT.
Correct value of LIBCOMPILER_RT.

Caught by:	Luca Bayer
Split in6_update_ifa() into smaller pieces leaving functionality intact.

Discussed with:	ae
MFC after:	2 weeks
Do some style(9) not done in r260851 to improve readability.

MFC after:	2 weeks
Style changes in vm_pageout_scan():

1. Be consistent in the style of "act_delta" manipulations between the
   inactive and active queue scans.

2. Explicitly compare to zero.

3. The deactivation of a page is based is based on its recent history
   and not just the current call to vm_pageout_scan().  The variable
   "act_delta" represents the current state of the page, and not its
   history.  Avoid possible confusion by not (ab)using "act_delta" for
   the making the deactivation decision.

Submitted by:	kib [1]
Reviewed by:	kib [2,3]
Add in6_prepare_ifra() function to ease preparing in-kernel IPv6
address requests.

MFC after:	2 weeks
Use in6_localip() instead of hand-rolled cycle.

MFC after:	2 weeks
Some processor's don't allow NMI injection if the STI_BLOCKING bit is set in
the Guest Interruptibility-state field. However, there isn't any way to
figure out which processors have this requirement.

So, inject a pending NMI only if NMI_BLOCKING, MOVSS_BLOCKING, STI_BLOCKING
are all clear. If any of these bits are set then enable "NMI window exiting"
and inject the NMI in the VM-exit handler.
Fix a bad comparison operator (s/==/=/), and address a use-case issue where-
in the one-line comment associated with the dumpdev setting was not present
for the case where the user deselects the dumpdev service (restoring pre-
r256348 behaviour.

MFC After:	3 days
Simplify filling sockaddr_dl structure for if_resolvemulti()
callback providers. link_init_sdl() function can be used to
fill most of the parameters. Use caller stack instead of
allocation / freing memory for each request. Do not drop support
for extra-long (probably non-existing) link-layer protocols by
introducing link_alloc_sdl() (used by if_resolvemulti() callback)
and link_free_sdl() (used by caller).
Since this change breaks KBI, MFC requires slightly different approach
(link_init_sdl() auto-allocating buffer if necessary to handle cases
 with unmodified if_resolvemulti() callers).

MFC after:	2 weeks
If the flowid is available for the mbuf that finalised the creation
of a syncache connection, copy it into the inp_flowid field.

Without this, an incoming TCP connection won't have an inp_flowid marked
until some data comes in, and this means that things like the per-CPU
TCP timer option will choose a different CPU for the timer work.
(It also means that if one grabbed the flowid via an ioctl from userland,
it won't be available until some data has been received.)

Sponsored by:	Netflix, Inc.
There's actually no data in the PMU_GET_VERSION command.  Don't send any.
This change now allows the PMU to be used on PowerBook5,8.

MFC after:	1 week
Revision 258428 changed gcc by virtue of having _bswapsi2 _bswapdi2 in
libgcc, but this was not propagated to this file. Revision 260844 added
them here for ia64 unbeknownst revision 258428. Fix it for all...

Pointed out by: pfg
Enable vt. This brings VGA-based console and terminal support to
ia64 for the very first time. Only 9 years in the making...

Note that the vt/vga driver does not actually make sure there's
VGA hardware at the standard/legacy VGA I/O port and memory I/O
addresses. This can cause machine checks if the H/W does not have
a VGA controller.
[automated] Merge in upstream-github/master