fix

Author: changvvb

compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala

@@ -247,7 +247,7 @@ object ExplicitOuter {
 
   /** Class constructor needs an outer argument. Can be called only after phase ExplicitOuter. */
   def needsOuterParam(cls: ClassSymbol)(using Context): Boolean =
-    !cls.is(Trait) && needsOuterAlways(cls)
+    !cls.is(Trait) && needsOuterIfReferenced(cls)
 
   /** Tree references an outer class of `cls` which is not a static owner.
    */