It's not clear to me why these functions are private. The clear use case for them is to allow a client to keep copy of a packet that was passed to its datafeed callback on the stack, and then free it later. They're not used internally at all, and never have been. We would need them public to fix bug #994 in the bindings.
Fixed in 3bae09ab9fc3681e0ae3d2f16e862c831d43efc3, thanks!