/usr/bin/llvm-objdump-3.8 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/bin/../lib/llvm-3.8/bin/llvm-objdump
/usr/bin/../lib/llvm-3.8/bin/llvm-objdump