Add original test and test with sealed class hierarchy

Author: odersky

tests/pos/i12508.scala

@@ -5,4 +5,13 @@ class Test {
       def x: X = ???
       def foo: Unit = this.x.toString
   }
+}
+class Test2 {
+  inline def test(fun: => Any): Any = fun
+  test {
+    case class Pair[X, Y](
+      x: X,
+      y: Y,
+    )
+  }
 }

tests/pos/i12508b.scala

@@ -0,0 +1,13 @@
+def fun(a: Any, b: Any = 2): Any = ???
+def test =
+  fun(
+    b = println(1),
+    a = {
+      sealed class Foo[X]:
+        def x: X = ???
+        def foo: Unit = this.x.toString
+      class Bar extends Foo[String]
+      class Baz[Y] extends Foo[Y]
+      if ??? then Bar() else Baz[Int]
+    }
+  )