open/open13.c: add O_PATH flag test

Basic test for O_PATH flag of open(2).
Obtain a file descriptor that can be used to perform operations
that act purely at the file descriptor level, the file itself is
not opened, the operations read(2), write(2), fchmod(2), fchown(2)
and fgetxattr(2) fail with the error EBADF.

Signed-off-by: Guangwen Feng <fenggw-fnst@cn.fujitsu.com>
6 files changed