Handle synthetic nodes use to throw exceptions

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

 // Copyright (c) 2015, 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.js_backend.helpers;
 
 import '../common.dart';
 import '../common/names.dart' show Identifiers, Uris;
 import '../common/resolution.dart' show Resolution;
 import '../compiler.dart' show Compiler;
@@ skipping 197 matching lines @@
   Element findHelper(String name) => find(jsHelperLibrary, name);
   Element findAsyncHelper(String name) => find(asyncLibrary, name);
   Element findInterceptor(String name) => find(interceptorsLibrary, name);
   Element find(LibraryElement library, String name) {
     Element element = library.implementation.findLocal(name);
     assert(invariant(library, element != null,
         message: "Element '$name' not found in '${library.canonicalUri}'."));
     return element;
   }
 
+  Element findCoreHelper(String name) =>
+      compiler.commonElements.coreLibrary.implementation.localLookup(name);
+
   ConstructorElement _findConstructor(ClassElement cls, String name) {
     cls.ensureResolved(resolution);
     ConstructorElement constructor = cls.lookupConstructor(name);
     assert(invariant(cls, constructor != null,
         message: "Constructor '$name' not found in '${cls}'."));
     return constructor;
   }
 
   void onLibraryCreated(LibraryElement library) {
     Uri uri = library.canonicalUri;
@@ skipping 398 matching lines @@
   }
 
   Element get checkDeferredIsLoaded {
     return findHelper('checkDeferredIsLoaded');
   }
 
   Element get throwNoSuchMethod {
     return findHelper('throwNoSuchMethod');
   }
 
+  Element get genericNoSuchMethod =>
+      _genericNoSuchMethod ??= findCoreHelper('_genericNoSuchMethod');
+  MethodElement _genericNoSuchMethod;
+
+  Element get unresolvedConstructorError => _unresolvedConstructorError ??=
+      findCoreHelper('_unresolvedConstructorError');
+  MethodElement _unresolvedConstructorError;
+
+  Element get malformedTypeError =>
+      _malformedTypeError ??= findCoreHelper('_malformedTypeError');
+  MethodElement _malformedTypeError;
+
   Element get createRuntimeType {
     return findHelper('createRuntimeType');
   }
 
   Element get fallThroughError {
     return findHelper("getFallThroughError");
   }
 
   Element get createInvocationMirror {
     return findHelper('createInvocationMirror');
@@ skipping 149 matching lines @@
   MethodElement _objectNoSuchMethod;
 
   MethodElement get objectNoSuchMethod {
     if (_objectNoSuchMethod == null) {
       _objectNoSuchMethod =
           coreClasses.objectClass.lookupLocalMember(Identifiers.noSuchMethod_);
     }
     return _objectNoSuchMethod;
   }
 }