scala#386 is fixed. Remove workaround

Author: DarkDimius

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

@@ -504,10 +504,7 @@ class DottyBackendInterface()(implicit ctx: Context) extends BackendInterface{
     def enclClass: Symbol = toDenot(sym).enclosingClass
     def linkedClassOfClass: Symbol = linkedClass
     def linkedClass: Symbol = {
-      val ct = ctx.withPhase(ctx.flattenPhase.prev)
-      toDenot(sym)(ct).linkedClass(ct)
-      // java.util.Attributes.Name$ -> java$util$Attributes$Name$ no companion class after flatten
-      // see bug #348
+      toDenot(sym)(ctx).linkedClass(ctx)
     } //exitingPickler(sym.linkedClassOfClass)
     def companionClass: Symbol = toDenot(sym).companionClass
     def companionModule: Symbol = toDenot(sym).companionModule