/usr/lib/x86_64-linux-gnu/libgomp.so is in libomp-dev 5.0.1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libomp.so.5
/usr/lib/x86_64-linux-gnu/libomp.so.5