/usr/mips64el-linux-gnuabi64/lib/libgnatprj.so is in libgnatprj5-dev-mips64el-cross 5.3.1-14ubuntu2cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/mips64el-linux-gnuabi64/lib/libgnatprj.so.5