/usr/lib/gcc-cross/i686-linux-gnu/6/libgphobos.so is in libgphobos-6-dev-i386-cross 6.4.0-17ubuntu1cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/gcc-cross/i686-linux-gnu/6/../../../../i686-linux-gnu/lib/libgphobos.so.68