Add support for listen() call.

MFC r317731:
Add Socklent for handling args of type socklen_t.

MFC r317732:
Decode the third argument of socket().

MFC r317736:
Add support for [gs]etsockopt().

MFC r317737:
Decode the fourth argument of sendto and recvfrom call.

MFC r317739:
Add support for sendmsg() and recvmsg().

MFC r317747:
Add support for socket option names related to the IPPROTO_SCTP level.

MFC r317748:
Add support for socket option names related to the IPPROTO_IPV6 level.

MFC r317750:
Add support for sctp_generic_sendmsg() and sctp_generic_recvmsg().

MFC r317789:
Add support for socket option names related to the level IPPROTO_UDPLITE.

MFC r318879:
Improve the decoding of the third argument of the socket() call.

Decoding of the third argument depends on the first one. For doing this,
add a corresponding function to libsysdecode.

Thanks to jhb@ for suggesting this.

Fix sysdecode_cap_rights which currently prints bogus capability rights.

PR:		217787

Fix libsysdecode vmprot flag decoding

Sponsored by:	Multiplay

307538:
Move mksubr from kdump into libsysdecode.

Restructure this script so that it generates a header of tables instead
of a source file.  The tables are included in a flags.c source file which
provides functions to decode various system call arguments.

For functions that decode an enumeration, the function returns a pointer
to a string for known values and NULL for unknown values.

For functions that do more complex decoding (typically of a bitmask), the
function accepts a pointer to a FILE object (open_memstream() can be used
as a string builder) to which decoded values are written.  If the
function operates on a bitmask, the function returns true if any bits
were decoded or false if the entire value was valid.  Additionally, the
third argument accepts a pointer to a value to which any undecoded bits
are stored.  This pointer can be NULL if the caller doesn't care about
remaining bits.

Convert kdump over to using decoder functions from libsysdecode instead of
mksubr.  truss also uses decoders from libsysdecode instead of private
lookup tables, though lookup tables for objects not decoded by kdump remain
in truss for now.  Eventually most of these tables should move into
libsysdecode as the automated table generation approach from mksubr is
less stale than the static tables in truss.

Some changes have been made to truss and kdump output:
- The flags passed to open() are now properly decoded in that one of
  O_RDONLY, O_RDWR, O_WRONLY, or O_EXEC is always included in a decoded
  mask.
- Optional arguments to open(), openat(), and fcntl() are only printed
  in kdump if they exist (e.g. the mode is only printed for open() if
  O_CREAT is set in the flags).
- Print argument to F_GETLK/SETLK/SETLKW in kdump as a pointer, not int.
- Include all procctl() commands.
- Correctly decode pipe2() flags in truss by not assuming full
  open()-like flags with O_RDONLY, etc.
- Decode file flags passed to *chflags() as file flags (UF_* and SF_*)
  rather than as a file mode.
- Fix decoding of quotactl() commands by splitting out the two command
  components instead of assuming the raw command value matches the
  primary command component.

In addition, truss and kdump now build without triggering any warnings.
All of the sysdecode manpages now include the required headers in the
synopsis.

307948:
Use binary and (&) instead of logical to extract the mask of a capability.

308602:
Generate and use a proper .depend file for tables.h.

308603:
Move libsysdecode-specific hack out of buildworld.

This should fix the lib32 build since it was not removing the generated
ioctl.c.  This file is generated by a find(1) call, so cannot use normal
dependency tracking methods.

311151:
Update libsysdecode for getfsstat() 'flags' argument changing to 'mode'.

As a followup to r310638, update libsysdecode (and kdump) to decode the
'mode' argument to getfsstat().  sysdecode_getfsstat_flags() has been
renamed to sysdecode_getfsstat_mode() and now treats the argument as an
enumerated value rather than a mask of flags.