Handle synthetic nodes use to throw exceptions

pkg/compiler/lib/src/js_backend/backend.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 js_backend.backend;
 
 import 'dart:async' show Future;
 
 import 'package:js_runtime/shared/embedded_names.dart' as embeddedNames;
 
@@ skipping 730 matching lines @@
         element.library == helpers.interceptorsLibrary ||
         element.library == helpers.isolateHelperLibrary) {
       // TODO(johnniwinther): We should be more precise about these.
       return true;
     } else if (element == coreClasses.listClass ||
         element == helpers.mapLiteralClass ||
         element == coreClasses.functionClass ||
         element == coreClasses.stringClass) {
       // TODO(johnniwinther): Avoid these.
       return true;
+    } else if (element == helpers.genericNoSuchMethod ||
+        element == helpers.unresolvedConstructorError ||
+        element == helpers.malformedTypeError) {
+      return true;
     }
     return false;
   }
 
   bool usedByBackend(Element element) {
     if (element.isRegularParameter ||
         element.isInitializingFormal ||
         element.isField) {
       if (usedByBackend(element.enclosingElement)) return true;
     }
@@ skipping 2465 matching lines @@
   ClassElement get mapImplementation => helpers.mapLiteralClass;
   ClassElement get constMapImplementation => helpers.constMapLiteralClass;
   ClassElement get typeImplementation => helpers.typeLiteralClass;
   ClassElement get boolImplementation => helpers.jsBoolClass;
   ClassElement get nullImplementation => helpers.jsNullClass;
   ClassElement get syncStarIterableImplementation => helpers.syncStarIterable;
   ClassElement get asyncFutureImplementation => helpers.futureImplementation;
   ClassElement get asyncStarStreamImplementation => helpers.controllerStream;
   ClassElement get functionImplementation => helpers.coreClasses.functionClass;
 }