MFC: r272243

  Add missing library dependencies.
MFC: r272245

  Remove duplicate prog.
MFC: r272248

  - Cleanups pc98 code.
  - Remove unworked formats.
MFC: r272252

  Drop the 3rd clause from all 3 clause BSD licenses.
MFC: r272258 (partial)
  - Reduce diffs against i386.

MFC: r272259
  MFi386: Enable QUOTA, PRINTF_BUFR_SIZE and puc.
MFC r271946 and r272595:
Improve transmit sending offload, TSO, algorithm in general. This
change allows all HCAs from Mellanox Technologies to function properly
when TSO is enabled. See r271946 and r272595 for more details about
this commit.

Sponsored by:	Mellanox Technologies
[SA-14:25] Fix kernel stack disclosure in setlogin(2) / getlogin(2).
[SA-14:26] Fix remote command execution in ftp(1).

Approved by:	so (des)
Revert r273860. It breaks IPSEC in tunnel mode and needs more revisions to
be merged before it will work as expected.
MFC r271992

  Reflect the chanages in sleepqueue.h and subr_sleepqueue.c
  - Priority argument is introduced to sleepq_*wait* in r177085
  - sleepq_calc_signal_retval is removed from implementation
  - sleepq_catch_signals is internal now

MFC r272475

  - Bump .Dd

Approved by:  kevlo
MFC: r273486
Clip the settings for the NFS rsize, wsize mount options
to a power of 2. For non-power of 2 settings, intermittent
page faults have been reported. Although the bug that causes
these page faults/crashes has not been identified, it does
not appear to occur when rsize, wsize is a power of 2.
MFC r273236:
Use pmc_destroy_pmc_descriptor() to actually free the pmc, which is
consistent with pmc_destroy_owner_descriptor(). Also be sure to destroy
PMCs if a process exits or execs without explicitly releasing them.
MFC r273342:
Fix a typo from r189544, which replaced unp_global_rwlock with unp_list_lock
and unp_link_rwlock.
Document SA-14:25, SA-14:26

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Bump __FreeBSD_version after SA-14:23, SA-14:24,
SA-14:25.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
MFC r273855:
  Fix mbuf leak in IPv6 multicast code.
  When multicast capable interface goes away, it leaves multicast groups,
  this leads to generate MLD reports, but MLD code does deffered send and
  MLD reports are queued in the in6_multi's in6m_scq ifq. The problem is
  that in6_multi structures are freed when interface leaves multicast groups
  and thread that does deffered send will not take these queued packets.

  PR:		194577

MFC r273857:
  Move ifq drain into in6m_purge().

  Suggested by:	bms
Sponsored by:	Yandex LLC