/usr/lib/x86_64-linux-gnu/gcj-6-17/libgcj_bc.so.1 is in libgcj17 6.3.0-18+deb9u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/gcj-6-17/../libgcj.so.17
/usr/lib/x86_64-linux-gnu/gcj-6-17/../libgcj.so.17