/usr/alpha-linux-gnu/lib/libgnatvsn.so is in libgnatvsn5-dev-alpha-cross 5.3.1-14ubuntu2cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/alpha-linux-gnu/lib/libgnatvsn.so.5
/usr/alpha-linux-gnu/lib/libgnatvsn.so.5