compat linux/linux32 uid16 functions cleanup+fixes

[Nicolas Joly <njoly%pasteur.fr@localhost>]

Hi,

While performing some regressions tests under compat linux/linux32, i
noticed that some uid16 functions were failing ... I started fixing
them; and while here, made some other cleanups :

- Add linux_sys_getres{uid,gid}16 to fix an overflow with incorrect
  sizes given to copyout.

- Move all uid16 functions to a new linux_uid16.c file, only included
  by needed archs (currently arm, i386 and m68k).

- Add some macros to handle conversions between linux_uid_t and uid_t
  (likewise for gid).

- Use linux_uid_t/linux_gid_t for syscalls arguments types where
  appropriate (instead of int, uid_t/gid_t, ...).

- Update arm syscall table to use more uid16 functions where
  applicable.

<URL:ftp://ftp.pasteur.fr/pub/computing/NetBSD/misc/netbsd-linuxuid16.diff>

Comments ?

-- 
Nicolas Joly

Biological Software and Databanks.
Institut Pasteur, Paris.