for sysv ipc stat operations, explicitly copy the exported parts
instead of the whole ds structure.

besides triggering a recently added assert in netbsd32, this stops
exposing kernel addresses.

copy the mode clamping to 0777 from sem to shm and msg.


while here, make sure that the compat callers to sysv_ipc clear
the contents of the compat structure before setting the result
members to ensure padding bytes are cleared.

don't set/copy _sem_base, _msg_first, _msg_last or _shm_internal.
even if used, which seems very dodgy, they leak KVAs as well.
possibly this may affect linux binaries, in particular, the
comments around _shm_internal ("XXX Oh well.") may mean apps
rely upon these but hopefully not -- the comments date back to
rev 1.1 in 1995.

the _key, _seq and _msg_cbytes members are exported as before as
i found multiple consumers of these (no less than ipcs(1), and
they appear to be useful for debugging and more.


XXX: the naming of compat functions have too many styles. there
are at least 3 different ones changed here.

branches: 1.6.40; 1.6.44; 1.6.52; 1.6.58;
Provide compatibility for pre-christos-time_t sysv sysctls.

merge christos-time_t

branches: 1.4.28; 1.4.30; 1.4.34; 1.4.44;
Expose semid_ds14_to_native() to otherparts of the system.
Don't leak kernel stack back to userspace.

branches: 1.3.20; 1.3.34; 1.3.36;
Copyright maintenance - only include the copyrights from the original
sys/*.h files that were in the files at the time the old structures
were present.

Move more compat stuff from sys.

branches: 1.1.6;
compat code reorg.