/usr/share/doc/libmudflap0-4.4-dev-armhf-cross is in libmudflap0-4.4-dev-armhf-cross 4.4.7-1ubuntu2cross1.52.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gcc-4.4-arm-linux-gnueabihf-base