/usr/share/doc/libasan1-dbg-powerpc-cross is in libasan1-dbg-powerpc-cross 4.9.3-13ubuntu2cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gcc-4.9-powerpc-linux-gnu-base
/usr/share/doc/gcc-4.9-powerpc-linux-gnu-base