MFC r263863:
  Dereference nonexistent md2(3) manual.

Sponsored by:	The FreeBSD Foundation
MFC r263460:
Take filedesc lock only for reading when allocating new fdtable.

Code populating the table does this already.
MFC r263530:
Mark the following sysctls as MPSAFE:
kern.file
kern.proc.filedesc
kern.proc.ofiledesc
MFC r263458:
audit: plug FILEDESC_LOCK leak in audit_canon_path.
MFC r263704:
Make /dev/devctl mpsafe.

MFC r263753:
Remove lockless check in devopen, while correct it does not make much sense.
MFC r263755:
Document a known problem with handling the process intended to receive
SIGIO in /dev/devctl.
MFC r263758:
Update userspace users of hw.bus.devctl_disable.

This switches the code to use hw.bus.devctl_queue instead.
MFC r263468:
  When loader(8) inspects MBR, it chooses GPT as main partition table,
  when MBR contains only PMBR entry or it is bootcamp-compatible.
  If MBR has PMBR entry and some other, the loader rejects it.

  Make these checks to be less strict. If loader decided that PMBR
  isn't suitable for GPT, it will use MBR.

  Reported by:	Paul Thornton
MFC r263271

share/man/man9/counter.9
	Fix logic error in the description of counter_u64_alloc: the command
	may fail only if M_NOWAIT is specified, not M_WAITOK.
MFC revisions 260894,260899,262895-262902,262904,262908-262910,262982,
262984,263133-263137,263139,263141,263144-263150, and (partially) 263249
(31 revisions; summarized below)...
r260894: Optimize f_expand_number(), improving performance
r260899: s/__number/__num/ in f_expand_number()
r262895: Allow dispatched reswords to carry arguments
r262896: Add missing local declaration
r262897: Fix a typo in a comment
r262898: Fix incorrect return status if var_to_set and var_to_get are same
r262899: Make f_show_err non-fatal
r262900: Centralize function name; Update a comment while here
r262901: s/__num/__number/ in f_expand_number()
r262902: Comment to go with NL global introduced by previous commit
r262904: Rewrite groupmgmt -- hooking it into the scripting system
r262908: Change dispatch words from group* to *Group for backward compat
r262909: Fix copy/paste error in a comment
r262910: Take a group name on the command-line if available
r262982: Whitespace
r262984: Remove vestigial global, no longer used since r262904
r263133: Remove indexfile from debug statement (already logged)
r263134: Add debug statement just before attempting to exec a module
r263135: Comments
r263136: Update copyright
r263137: Fix future namespace issues for functions taking $var_to_set
r263139: Remove useless NULL string in compound strings
r263141: Pointy hat! Fix a broken f_isinteger()
r263144: Fix a code-typo that prevented auto-sizing of a dialog
r263145: Fix comments and whitespace
r263146: Reduce the sleep cycle when using dialog(1) [infobox] to 1-second
r263147: Fix a bug preventing errors from pw(8) from appearing
r263148: For non-interactive scripts, forgot to check argument
r263149: Add protection against input containing single-quotes
r263150: Rewrite usermgmt
r263249: (partial) Add more obsolete files
MFC r263891:

Make clang default to DWARF2 debug info format for FreeBSD 10.x and
earlier.  For head, this commit does not change anything, but it is
purely meant to be MFC'd.
MFC r263118:
Report ZVOL block size as GEOM stripesize.