Although the Linux syscall renameat2 is not in glibc (yet?), it is
useful to have access to its RENAME_NOREPLACE flag.
* MODULES.html.sh (func_all_modules): Add renameat2.
* lib/renameat2.c, lib/renameat2.h, modules/renameat2:
* modules/renameat2-tests, tests/test-renameat2.c: New files.
* lib/renameat.c (renameat): Move most of the implementation
to renameat2, and just call renameat2.
* modules/renameat (Files): Remove lib/at-func2.c.
(Depends-on): Depend only on renameat2.
(Include): Remove <fcntl.h>.
* modules/renameat-tests (test_renameat_LDADD): Add $(LIB_EACCESS),
since renameat (via renameat2) might use faccessat.