Any aircraft can fly itself. Automation in flight systems is not new nor does it even require a computer. Negative feedback systems in both machines and in biology can do it very well -- in insects and birds it happens beautifully.
Early autopilots were analogue and worked remarkably well. Drones can keep flying and gliding without help (as long as they have power and fuel) -- of course they can. Its a classic and ancient application. But right now that makes them one step above a paper dart -- all be it with weaponry and reconnaissance. And that don't work without human intervention.
They are merely a remote extension of their human pilot's hand. Thankfully, because no one wants an autonomous drone going off on its own to "discover itself".