scala/scala — pull request #3797 by retronym (2014-05-28 13:22:20+00:00)
Title: SI-8631 Treat `A with Sealed` as enumerable for pattern matching

Enumerate the subtypes of sealed parent types of refinement
types, and filter those that conform to the refinement type.

Such types can crop up easily when LUB-bing case classes which
add `Product with Serializable` to the mix.