/usr/s390x-linux-gnu/bin/ar is in binutils-s390x-linux-gnu 2.30-20ubuntu2~18.04.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/s390x-linux-gnu/bin/../../bin/s390x-linux-gnu-ar
/usr/s390x-linux-gnu/bin/../../bin/s390x-linux-gnu-ar