/usr/share/doc/llvm-dev/NEWS.Debian.gz is in llvm-dev 1:6.0-41~exp4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/llvm-dev/../llvm-runtime/NEWS.Debian.gz
/usr/share/doc/llvm-dev/../llvm-runtime/NEWS.Debian.gz