/usr/share/doc/gdc-5-arm-linux-gnueabihf/changelog.Debian.gz is in gdc-5-arm-linux-gnueabihf 5.3.1-14ubuntu2cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gdc-5-arm-linux-gnueabihf/../gcc-5-arm-linux-gnueabihf-base/changelog.Debian.gz