/usr/share/doc/gobjc++-5-multilib-mips64-linux-gnuabi64 is in gobjc++-5-multilib-mips64-linux-gnuabi64 5.3.1-14ubuntu2cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gcc-5-mips64-linux-gnuabi64-base