Pre-RFC: Deprecation and separation of the dead_code lint

That's a fair point. I don't think unused_items covering all items was in the original proposal when I read it.

That addresses one of my concerns, and I think it is an improvement. But I think the churn caused by a deprecation here is not worth it. dead_code is very widely used. I don't think deprecation is necessary for improvement here though, to be clear.