Fix some bad interaction between cxgbe(4) and lacp lagg(4) that could
leave a port permanently disabled when a copper cable is unplugged and
then plugged right back in.

lacp_linkstate goes looking for the current ifmedia on a link state
change and it could get stale information from cxgbe(4) on a module
unplug followed by replug.  The fix is to process module events before
link-state events within the driver, and to always rebuild the ifmedia
list on a module change event (instead of rebuilding it lazily).

Thanks to asomers@ for the problem report and detailed analysis to go
with it.

MFC after:	1 week
we need full barriers here
Derive copyright year from src/COPYRIGHT.

MFC after:	2 weeks
add support for private knote lock (reduces lock contention),
adapting OS_selrecord accordingly.
Problem and fix suggested by adrian and jmg
Increase MAXTABLE to the maxmimum possible value.  The default value is too
low for complex parsers.  Note it was one of those memory optimization hacks
back in the day.

MFC after:	1 week
iw_cxgbe: don't forget to close the socket in c4iw_connect if soconnect
fails.

Submitted by:	hariprasad at chelsio dot com
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Add the ppoll() system call.
Export kern_poll() needed by an upcoming Linuxulator change.

Differential Revision:	https://reviews.freebsd.org/D1133
Reviewed by:	kib, wblock
MFC after:	1 month
Regen for r274462.
Remove redundant ip6_plen initialization.

MFC after:	1 week
Sponsored by:	Yandex LLC
Strip IP header only when we act in tunnel mode.

MFC after:	1 week
Sponsored by:	Yandex LLC
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Count statistics for the specific address family.

MFC after:	1 week
Sponsored by:	Yandex LLC
Bump FreeBSD_version for r274462 - add ppoll() system call.
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Merge branch 'hardened/current/master' into hardened/current/unstable

Conflicts:
	sys/compat/freebsd32/freebsd32_proto.h
	sys/compat/freebsd32/freebsd32_syscall.h
	sys/compat/freebsd32/freebsd32_syscalls.c
	sys/compat/freebsd32/freebsd32_sysent.c
	sys/compat/freebsd32/freebsd32_systrace_args.c
	sys/compat/freebsd32/syscalls.master
	sys/kern/init_sysent.c
	sys/kern/syscalls.c
	sys/kern/syscalls.master
	sys/kern/systrace_args.c
	sys/sys/syscall.h
	sys/sys/syscall.mk
	sys/sys/sysproto.h