/usr/share/doc/libmudflap0-dbg-armel-cross is in libmudflap0-dbg-armel-cross 4.6.3-1ubuntu5cross1.62.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gcc-4.6-arm-linux-gnueabi-base
/usr/share/doc/gcc-4.6-arm-linux-gnueabi-base