/usr/lib/x86_64-linux-gnu/libmozjs-24.so is in libmozjs-24-dev 24.2.0-5.1+b2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmozjs-24.so.0
/usr/lib/x86_64-linux-gnu/libmozjs-24.so.0