/usr/lib/gcc/arm-linux-gnueabihf/4.6/libmudflapth.so is in libmudflap0-4.6-dev-armhf-cross 4.6.3-1ubuntu5cross1.63.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../../arm-linux-gnueabihf/lib/libmudflapth.so.0