Approximate annotated types in wildApprox

Author: mbovel

Diff for: compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala

@@ -1017,6 +1017,8 @@ object ProtoTypes {
         paramInfos = tl.paramInfos.mapConserve(wildApprox(_, theMap, seen, internal1).bounds),
         resType = wildApprox(tl.resType, theMap, seen, internal1)
       )
+    case AnnotatedType(parent, _) =>
+      WildcardType(TypeBounds.upper(wildApprox(parent, theMap, seen, internal)))
     case _ =>
       (if (theMap != null && seen.eq(theMap.seen)) theMap else new WildApproxMap(seen, internal))
         .mapOver(tp)

Diff for: tests/pos/annot-default-arg-22839.scala

@@ -0,0 +1,5 @@
+package defaultArgBug
+
+class annot(arg: Int) extends scala.annotation.StaticAnnotation
+
+def foo(a: Int, b: Int @annot(a + a) = 42): Int = b