/usr/share/doc/llvm-3.8/changelog.Debian.gz is in llvm-3.8 1:3.8-2ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/llvm-3.8/../llvm-3.8-runtime/changelog.Debian.gz
/usr/share/doc/llvm-3.8/../llvm-3.8-runtime/changelog.Debian.gz