/usr/arm-linux-gnueabihf/lib/libgnat.so is in gnat-5-arm-linux-gnueabihf 5.5.0-12ubuntu1cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/arm-linux-gnueabihf/lib/libgnat-5.so.1
/usr/arm-linux-gnueabihf/lib/libgnat-5.so.1