Handle parameters in compile_from_dill_test

tests/compiler/dart2js/equivalence/check_functions.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// Equivalence test functions for data objects.
 
 library dart2js.equivalence.functions;
 
 import 'package:expect/expect.dart';
 import 'package:compiler/src/common/resolution.dart';
@@ skipping 190 matching lines @@
       }
       Expect.isFalse(
           child.isInstantiated,
           'Missing subclass ${child.cls} of ${node1.cls} in '
           '${node2.directSubclasses}');
     }
   }
   checkMixinUses(
       closedWorld1, closedWorld2, node1.cls, node2.cls, elementEquivalence,
       verbose: verbose);
+  Expect.isNotNull(closedWorld1.getClassSet(cls1));
+  Expect.isNotNull(closedWorld2.getClassSet(cls2));
 }
 
 void checkMixinUses(
     ClosedWorld closedWorld1,
     ClosedWorld closedWorld2,
     ClassEntity class1,
     ClassEntity class2,
     bool elementEquivalence(Entity a, Entity b),
     {bool verbose: false}) {
   checkSets(closedWorld1.mixinUsesOf(class1), closedWorld2.mixinUsesOf(class2),
@@ skipping 562 matching lines @@
       areAbstractUsagesEquivalent,
       verbose: verbose);
   checkMaps(
       worldBuilder1.instanceMemberUsageForTesting,
       worldBuilder2.instanceMemberUsageForTesting,
       'instanceMemberUsageForTesting',
       elementEquivalence,
       areAbstractUsagesEquivalent,
       verbose: verbose);
 }