/usr/lib/llvm-6.0/bin/llvm-dlltool is in llvm-6.0 1:6.0-1ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/llvm-6.0/bin/llvm-ar
/usr/lib/llvm-6.0/bin/llvm-ar