Extract OrderedTypeSetBuilderBase from OrderedTypeSetBuilder

pkg/compiler/lib/src/deferred_load.dart

 // Copyright (c) 2014, 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 deferred_load;
 
 import 'common/tasks.dart' show CompilerTask;
 import 'common.dart';
 import 'compiler.dart' show Compiler;
 import 'constants/expressions.dart' show ConstantExpression;
@@ skipping 414 matching lines @@
       // extra dependencies due to mirrors.
       void addLiveInstanceMember(_, MemberElement element) {
         if (!compiler.resolutionWorldBuilder.isMemberUsed(element)) return;
         if (!isMirrorUsage && !element.isInstanceMember) return;
         elements.add(element);
         collectDependencies(element);
       }
 
       ClassElement cls = element.declaration;
       cls.implementation.forEachMember(addLiveInstanceMember);
-      for (var type in cls.implementation.allSupertypes) {
+      for (ResolutionInterfaceType type in cls.implementation.allSupertypes) {
         elements.add(type.element.implementation);
       }
       elements.add(cls.implementation);
     } else if (Elements.isStaticOrTopLevel(element) || element.isConstructor) {
       elements.add(element);
       collectDependencies(element);
     }
     if (element.isGenerativeConstructor) {
       // When instantiating a class, we record a reference to the
       // constructor, not the class itself.  We must add all the
@@ skipping 615 matching lines @@
 
   bool operator ==(other) {
     if (other is! _DeclaredDeferredImport) return false;
     return declaration == other.declaration;
   }
 
   int get hashCode => declaration.hashCode * 17;
 
   String toString() => '$declaration';
 }