Spec followup to #3747

[OlivierBlanvillain]

#3747 changes pattern matching to allow "Pattern Sequences" to be used on unapply (where unapplySeq was previously required). This needs a spec change, this page would probably be a good place to do that.

[odersky]

I have too much on my plate. I need someone else to take over the pattern matching chapter. This could be a good thing to start with!

EDIT: Never mind - I added the description. But it would still be very important that someone takes over the pattern matching area - it's a rich source of problems, a lot of them academically interesting, and completely under-studied so far.

[Blaisorblade]

Adding to my queue — with no time estimate yet.

[odersky]

We should not let things linger like that. The more open PRs we have the more everyone's productivity suffers.