* modules/chdir-long (Depends-on): Remove mempcpy.

* modules/chdir-long (Depends-on): Remove mempcpy.

* lib/openat.h (AT_SYMLINK_NOFOLLOW): Define to 4096, so it's the
same value as for Solaris 9.

* lib/chdir-long.c (chdir_long): Rewrite to remove limitation on
component length.  This included changing the parameter to be
of type `char *' rather than `char const *'.
* lib/chdir-long.h (chdir_long): Update prototype.

* lib/openat.c (fdopendir, fstatat): New functions.
* lib/openat.h: Include headers required for use of DIR and struct stat.
[AT_SYMLINK_NOFOLLOW]: Define.
(fdopendir, fstatat): Add prototypes.