/usr/powerpc64-linux-gnu/lib/libgnarl.so is in gnat-5-powerpc64-linux-gnu 5.3.1-14ubuntu2cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/powerpc64-linux-gnu/lib/libgnarl-5.so.1
/usr/powerpc64-linux-gnu/lib/libgnarl-5.so.1