Make changeOwnerAfter skip weak owners

changeOwner already does this.

Author: odersky

compiler/src/dotty/tools/dotc/ast/tpd.scala

@@ -629,7 +629,7 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
           case tree: DefTree =>
             val sym = tree.symbol
             val prevDenot = sym.denot(ctx.withPhase(trans))
-            if (prevDenot.owner == from) {
+            if (prevDenot.effectiveOwner == from.skipWeakOwner) {
               val d = sym.copySymDenotation(owner = to)
               d.installAfter(trans)
               d.transformAfter(trans, d => if (d.owner eq from) d.copySymDenotation(owner = to) else d)