Use entities in interceptor_stub_generator.

pkg/compiler/lib/src/js_backend/custom_elements_analysis.dart

 // Copyright (c) 2013, 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.
 
 import '../compiler.dart' show Compiler;
 import '../constants/values.dart';
 import '../elements/resolution_types.dart';
 import '../elements/elements.dart';
 import '../enqueue.dart' show Enqueuer;
 import '../universe/use.dart' show StaticUse;
@@ skipping 108 matching lines @@
   /// Computes the [WorldImpact] of the classes registered since last flush.
   WorldImpact flush({bool forResolution}) {
     return joinFor(forResolution: forResolution).flush();
   }
 
   bool get needsTable => codegenJoin.demanded;
 
   bool needsClass(ClassElement classElement) =>
       codegenJoin.activeClasses.contains(classElement);
 
-  List<Element> constructors(ClassElement classElement) =>
+  List<ConstructorElement> constructors(ClassElement classElement) =>
       codegenJoin.computeEscapingConstructors(classElement);
 }
 
 class CustomElementsAnalysisJoin {
   final JavaScriptBackend backend;
   Compiler get compiler => backend.compiler;
 
   final StagedWorldImpactBuilder impactBuilder = new StagedWorldImpactBuilder();
 
   // Classes that are candidates for needing constructors.  Classes are moved to
@@ skipping 71 matching lines @@
           result.add(member);
         }
       }
     }
 
     classElement.forEachMember(selectGenerativeConstructors,
         includeBackendMembers: false, includeSuperAndInjectedMembers: false);
     return result;
   }
 }