fchmodat, fchownat, fstatat: port to non-inlining compilers

fchmodat, fchownat, fstatat: port to non-inlining compilers

Problem reported for FreeBSD 9 by Jim Meyering in
<http://lists.gnu.org/archive/html/bug-gnulib/2012-10/msg00070.html>.
* lib/chmodat.c, lib/chownat.c, lib/statat.c:
New files, which define FCHMODAT_INLINE etc.
* lib/fchmodat.c (FCHMODAT_INLINE):
* lib/fchownat.c (FCHOWNAT_INLINE):
* lib/fstatat.c (FSTATAT_INLINE):
Remove, as chmodat.c etc. now do this.
* modules/fchmodat (Files): Add lib/chmodat.c.
* modules/fchownat (Files): Add lib/chownat.c.
* modules/fstatat (Files): Add lib/statat.c.