Also mutate module *class*'s owner in ChangeOwnerTraverser

Keep owner for module (symbol of the tree) and module class (holds the members)
in synch while moving trees between owners (e.g., while duplicating them in specialization)

Author: adriaanm

src/reflect/scala/reflect/internal/Trees.scala

@@ -1468,8 +1468,10 @@ trait Trees extends api.Trees {
 
   class ChangeOwnerTraverser(val oldowner: Symbol, val newowner: Symbol) extends Traverser {
     final def change(sym: Symbol) = {
-      if (sym != NoSymbol && sym.owner == oldowner)
+      if (sym != NoSymbol && sym.owner == oldowner) {
         sym.owner = newowner
+        if (sym.isModule) sym.moduleClass.owner = newowner
+      }
     }
     override def traverse(tree: Tree) {
       tree match {