/usr/libx32/libquadmath.so.0 is in libx32quadmath0 4.8.4-2ubuntu1~14.04.4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/libx32/libquadmath.so.0.0.0
/usr/libx32/libquadmath.so.0.0.0