Post #3035592

Took `strictEqualityPatternMatching` and `subCases` for a test ride. `strictEqualityPatternMatching` works pretty good. also across `sum`/`enum` types and `union` types. Nice! `subCases` interfered with exhaustivity checks. Maybe I am doing something wrong. `subCases` for `sum` types to tease them out separately would be solid. `Integer` pattern match was deemed exhaustive when shouldn't have been. (will do some more tests here.) https://scastie.scala-lang.org/CE9rW97WRSSnFkQsP83TKg #scala #scastie