Use ClassHierarchy.applyChanges() in MixinFullResolution.

pkg/kernel/lib/transformations/mixin_full_resolution.dart

 // Copyright (c) 2016, 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.
 library kernel.transformations.mixin_full_resolution;
 
 import '../ast.dart';
 import '../class_hierarchy.dart';
 import '../clone.dart';
 import '../core_types.dart';
 import '../target/targets.dart' show Target;
@@ skipping 35 matching lines @@
     // the mixin and constructors from the base class.
     var processedClasses = new Set<Class>();
     for (var library in libraries) {
       if (library.isExternal) continue;
 
       for (var class_ in library.classes) {
         transformClass(libraries, processedClasses, transformedClasses, class_);
       }
     }
 
-    // If there are transformed classes, we need to update hierarchy.
-    if (transformedClasses.isNotEmpty) {
-      var program = libraries.first.enclosingProgram;
-      hierarchy = new ClosedWorldClassHierarchy(program);
-    }
+    // We might need to update the class hierarchy.
+    hierarchy = hierarchy.applyChanges(transformedClasses);
 
     // Resolve all super call expressions and super initializers.
     for (var library in libraries) {
       if (library.isExternal) continue;
 
       for (var class_ in library.classes) {
         final bool hasTransformedSuperclass =
             transformedClasses.contains(class_.superclass);
 
         for (var procedure in class_.procedures) {
@@ skipping 273 matching lines @@
           return null;
         }
       }
 
       throw new Exception(
           'Could not find a generative constructor named "${constructor.name}" '
           'in lookup class "${lookupClass.name}"!');
     }
   }
 }