/usr/lib/llvm-4.0/bin/lldb-mi is in lldb-4.0 1:4.0-1ubuntu1~16.04.2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/llvm-4.0/bin/lldb-mi-4.0.0
/usr/lib/llvm-4.0/bin/lldb-mi-4.0.0