MFC 254699,255030:
Use tvtohz() to convert a socket buffer timeout to a tick value rather
than using a home-rolled version.  The home-rolled version could result
in shorter-than-requested sleeps.

PR:		kern/181416
MFC 255248:
Use an unsigned long when indexing into mfchashtbl[] and mf6ctable[].  This
matches the types used when computing hash indices and the type of the
maximum size of mfchashtbl[].

PR:		kern/181821
MFC 255490,255491:
Fix the type of the idtype argument to wait6() in syscalls.master.
Regen.
MFC 255497:
Fix an off-by-one error when populating mincore(2) entries for
skipped entries.  lastvecindex references the last valid byte,
so the new bytes should come after it.
MFC 255498:
- Document the UQUAD sysctl variants.
- Clarify that exactly one of the "access" flags is required and
  list the optional flags in a separate list.  Prefer bundling
  CTLFLAG_TUN into the access flag by not documenting it as an
  optional flag to set.
MFC r257858:
Fix signal delivery for the iBCS2 binaries.
MFC r257856:
Add bits for the AMD features from CPUID function 0x80000001 ECX,
described in the rev. 3.0 of the Kabini BKDG, document 48751.pdf.
MFC 256293:
Sanitize the %eflags returned by BIOS routines.  Some BIOS routines enter
protected mode and may leave protected-mode-specific flags like PSL_NT set
when they return to real mode.  This can cause a fault when BTX re-enters
protected mode after the BIOS mode returns.

PR:		amd64/182740
MFC 256274:
Ignore attempts to set the nmbcluster sysctls to their current value
rather than failing with an error.
MFC 257006

sbin/geom/class/part/geom_part.c
        Always validate the return of find_geomcfg().  It could be NULL, for
        example when the geom is withering.

Approved by:	ken(mentor)
Sponsored by:	Spectra Logic Corporation
Merge remote-tracking branch 'upstream/stable/9' into stable/9