/usr/lib/gcc/arm-linux-gnueabihf/4.5.3/libmudflapth.so is in libmudflap0-4.5-dev-armhf-cross 4.5.3-12ubuntu2cross1.61.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/gcc/arm-linux-gnueabihf/4.5.3/../../../../arm-linux-gnueabihf/lib/libmudflapth.so.0