Tests for `void`.

pkg/compiler/lib/src/common/backend_api.dart

 // Copyright (c) 2012, 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 dart2js.backend_api;
 
 import 'dart:async' show Future;
 
 import '../common.dart';
 import '../common/codegen.dart' show CodegenImpact;
@@ skipping 373 matching lines @@
 /// Interface for serialization of backend specific data.
 class BackendSerialization {
   const BackendSerialization();
 
   SerializerPlugin get serializer => const SerializerPlugin();
   DeserializerPlugin get deserializer => const DeserializerPlugin();
 }
 
 /// Interface providing access to core classes used by the backend.
 abstract class BackendClasses {
+
+  /// Returns the backend implementation class for `void`.
+  ClassEntity get voidClass;
+
   /// Returns the backend implementation class for `int`. This is the `JSInt`
   /// class.
   ClassEntity get intClass;
 
   /// Returns the backend implementation class for `double`. This is the
   /// `JSDouble` class.
   ClassEntity get doubleClass;
 
   /// Returns the backend implementation class for `num`. This is the `JSNum`
   /// class.
@@ skipping 100 matching lines @@
   /// Returns `true` if [cls] is an intercepted class.
   // TODO(johnniwinther): Rename this to `isInterceptedClass`.
   bool isInterceptorClass(ClassEntity cls);
 
   /// Returns `true` if [cls] is a native class.
   bool isNativeClass(ClassEntity element);
 
   /// Returns `true` if [element] is a native member of a native class.
   bool isNativeMember(MemberEntity element);
 }