/usr/lib/x86_64-linux-gnu/libSDL_ttf.so is in libsdl-ttf2.0-dev 2.0.11-4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libSDL_ttf-2.0.so.0.10.1
/usr/lib/x86_64-linux-gnu/libSDL_ttf-2.0.so.0.10.1