/usr/lib/gcc-cross/arm-linux-gnueabi/7/libgphobos.so is in libgphobos-7-dev-armel-cross 7.3.0-16ubuntu3cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/gcc-cross/arm-linux-gnueabi/7/../../../../arm-linux-gnueabi/lib/libgphobos.so.71