/usr/share/doc/cpp-mips64-linux-gnuabi64/README.Bugs is in gcc-mips64-linux-gnuabi64 4:6.3.0-4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/cpp-mips64-linux-gnuabi64/../gcc-6-base/README.Bugs