/usr/mipsel-linux-gnu/lib32/libgfortran.so.5 is in libn32gfortran5-mipsel-cross 8-20180414-1ubuntu2cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/mipsel-linux-gnu/lib32/libgfortran.so.5.0.0