Remove code for impossible or ill cases

Author: liufengyun

compiler/src/dotty/tools/dotc/transform/init/Summarization.scala

@@ -253,12 +253,12 @@ object Summarization {
 
   def resolveThis(cls: ClassSymbol, pot: Potential, cur: ClassSymbol, source: Tree)(implicit env: Env): Summary =
   trace("resolve " + cls.show + ", pot = " + pot.show + ", cur = " + cur.show, init, s => Summary.show(s.asInstanceOf[Summary])) {
-    val enclosing = cur.owner.lexicallyEnclosingClass.asClass
     if (cls.is(Flags.Package)) (Potentials.empty, Effects.empty)
-    else if (cls == cur || enclosing.is(Flags.Package)) (pot.toPots, Effects.empty)
+    else if (cls == cur) (pot.toPots, Effects.empty)
     else if (pot.size > 2) (Potentials.empty, Promote(pot)(source).toEffs)
     else {
       val pot2 = Outer(pot, cur)(pot.source)
+      val enclosing = cur.owner.lexicallyEnclosingClass.asClass
       resolveThis(cls, pot2, enclosing, source)
     }
   }