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