/usr/bin/aarch64-linux-gnu-gdc is in gdc-aarch64-linux-gnu 4:5.3.1-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/aarch64-linux-gnu-gdc-5
/usr/bin/aarch64-linux-gnu-gdc-5