Drop package facades: JVM BE tests passed.

compiler/testData/codegen/boxWithJava/builtinStubMethods/substitutedIterable/Test.java

@@ -1,7 +1,7 @@
 public class Test {
     public static void checkCallFromJava() {
         try {
-            String x = _DefaultPackage.foo().iterator().next();
+            String x = SubstitutedIterableKt.foo().iterator().next();
             throw new AssertionError("E should have been thrown");
         } catch (E e) { }
     }