scala.swing.Scrollable does not implement javax.swing.Scrollable in peer

[scabug]

A component that extends scala.swing.Scrollable (but not Scrollable.Wrapper) should cause the component's peer to implement javax.swing.Scrollable and forward the latter's methods to the former. That way, custom components can be made scrollable.

In 2.8.0, this is not the case. Rather, extending scala.swing.Scrollable and implementing its methods for a custom scrollable component has no effect, since the resulting peer doesn't implement javax.swing.Scrollable.

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-3823?orig=1
Reporter: Alex Hvostov (argv)