Add test case

Author: OlivierBlanvillain

tests/pos/10747-shapeless-min.scala

@@ -0,0 +1,12 @@
+trait Monoidal {
+  type to[_] <: Tuple
+}
+
+object eithers extends Monoidal {
+  class Wrap[T]
+
+  type to[t] <: Tuple = Wrap[t] match {
+    case Wrap[Either[hd, tl]] => hd *: to[tl]
+    case Wrap[Nothing] => EmptyTuple
+  }
+}