/usr/share/doc/libobjc4-dbg-armel-cross is in libobjc4-dbg-armel-cross 4.7.3-12ubuntu1cross1.85.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gcc-4.7-arm-linux-gnueabi-base
/usr/share/doc/gcc-4.7-arm-linux-gnueabi-base