/usr/sh4-linux-gnu/lib/libgnarl.so is in gnat-7-sh4-linux-gnu 7.3.0-16ubuntu3cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/sh4-linux-gnu/lib/libgnarl-7.so.1
/usr/sh4-linux-gnu/lib/libgnarl-7.so.1