[Pitch] Conditionally conform Optional: Sequence where Wrapped: Sequence

Evolution Pitches
2

Another one that make sense to add, when SE-0134 is implemented, is Hashable, so that we can have Sets and Dictionary(s) of Optionals:

extension Optional: Hashable where Wrapped: Hashable {
	var hashValue: Int {
		return self?.hashValue ?? 0
	}
}

I'm sure there are more, which makes me wonder: is something like this scalable? Will we end up with a hundred different extensions to Optional for each protocol which has a "default" for Optional?