/usr/lib/x86_64-linux-gnu/libunity-mir.so is in libunity-mir-dev 0.3+14.04.20140417-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libunity-mir.so.1
/usr/lib/x86_64-linux-gnu/libunity-mir.so.1