/usr/lib/gcc-cross/powerpc-linux-gnu/4.8/64/libgfortran.so is in lib64gfortran-4.8-dev-powerpc-cross 4.8.2-16ubuntu3cross0.11.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/gcc-cross/powerpc-linux-gnu/4.8/64/../../../../../powerpc-linux-gnu/lib64/libgfortran.so.3