dart2js: add work-around hack for try.

pkg/dart2js_incremental/lib/library_updater.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 dart2js_incremental.library_updater;
 
 import 'dart:async' show
     Future;
 
 import 'dart:convert' show
@@ skipping 48 matching lines @@
 import 'package:compiler/src/js/js.dart' as jsAst;
 
 import 'package:compiler/src/js_emitter/js_emitter.dart' show
     ClassBuilder,
     ClassEmitter,
     CodeEmitterTask,
     ContainerBuilder,
     MemberInfo,
     computeMixinClass;
 
+import 'package:compiler/src/js_emitter/model.dart' show
+    Class;

[ahe, 2015/01/28 07:22:37]

Add newline between imports.

[floitsch, 2015/01/28 16:25:05]

Done.

+import 'package:compiler/src/js_emitter/program_builder.dart' show
+    ProgramBuilder;
+
 import 'package:_internal/compiler/js_lib/shared/embedded_names.dart'
     as embeddedNames;
 
 import 'package:compiler/src/js_backend/js_backend.dart' show
     JavaScriptBackend,
     Namer;
 
 import 'package:compiler/src/util/util.dart' show
     Link,
     LinkBuilder;
@@ skipping 1382 matching lines @@
   EnqueueTask get enqueuer => compiler.enqueuer;
 }
 
 class EmitterHelper extends JsFeatures {
   final Compiler compiler;
 
   EmitterHelper(this.compiler);
 
   ClassEmitter get classEmitter => backend.emitter.oldEmitter.classEmitter;
 
-  List<String> computeFields(ClassElement cls) {
+  List<String> computeFields(ClassElement classElement) {
+    Class cls = new ProgramBuilder(compiler, namer, emitter)
+        .buildClassWithFieldsForTry(classElement);
     // TODO(ahe): Rewrite for new emitter.
-    ClassBuilder builder = new ClassBuilder(cls, namer);
+    ClassBuilder builder = new ClassBuilder(classElement, namer);
     classEmitter.emitFields(cls, builder);
     return builder.fields;
   }
 }
 
 // TODO(ahe): Remove this method.
 NO_WARN(x) => x;