Handle inner classes defined in suppercalls.

Author: DarkDimius

src/dotty/tools/backend/jvm/DottyBackendInterface.scala

@@ -485,7 +485,7 @@ class DottyBackendInterface()(implicit ctx: Context) extends BackendInterface{
           val original = toDenot(sym).initial
           val validity = original.validFor
           val shiftedContext = ctx.withPhase(validity.phaseId)
-          val r = toDenot(sym)(shiftedContext).maybeOwner
+          val r = toDenot(sym)(shiftedContext).maybeOwner.enclosingClass(shiftedContext)
           r
         } else NoSymbol
       } catch {

src/dotty/tools/dotc/core/SymDenotations.scala

@@ -716,6 +716,9 @@ object SymDenotations {
      *  but in turn the enclosing class of the latter. This reflects
      *  the context created by `Context#superCallContext`, `Contect#thisCallArgContext`
      *  for these definitions.
+     *
+     *  Note, that as packages have ClassSymbols, top level classes will have an `enclosingClass`
+     *  with Package flag set.
      */
     final def enclosingClass(implicit ctx: Context): Symbol = {
       def enclClass(sym: Symbol, skip: Boolean): Symbol = {