/usr/x86_64-linux-gnux32/lib64/libgdruntime.so.76 is in lib64gphobos76-x32-cross 8-20180414-1ubuntu2cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/x86_64-linux-gnux32/lib64/libgdruntime.so.76.0.2