/usr/lib/x86_64-linux-gnu/libmysqld.so is in libmariadbd-dev 10.0.32-0+deb8u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmysqld.so.18
/usr/lib/x86_64-linux-gnu/libmysqld.so.18