setresuid/setresuid04.c: Add new test

1. Set new euid.
2. Create a new file.
3. Verify the file's st_uid is equal to the new euid.

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>
setresgid/setresgid04.c: Add new test

1. Set new egid.
2. Create a new file.
3. Verify the file's st_gid is equal to the new egid.

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>