Introduce .isMalformed

pkg/compiler/lib/src/library_loader.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.library_loader;
 
 import 'dart:async';
 
 import 'common.dart';
 import 'common/names.dart' show
@@ skipping 957 matching lines @@
           message: "No export for $duplicate from ${duplicate.library} "
                    "in $library."));
       infos.add(reporter.createMessage(
           duplicate,
               MessageKind.DUPLICATE_EXPORT_DECL,
           {'name': name, 'uriString': duplicateExports.head.uri}));
     }
 
     Element existingElement = exportScope[name];
     if (existingElement != null && existingElement != element) {
-      if (existingElement.isErroneous) {
+      if (existingElement.isMalformed) {
         createDuplicateExportMessage(element, exports);
         createDuplicateExportDeclMessage(element, exports);
         element = existingElement;
       } else if (existingElement.library == library) {
         // Do nothing. [existingElement] hides [element].
       } else if (element.library == library) {
         // [element] hides [existingElement].
         exportScope[name] = element;
         exporters[element] = exports;
       } else {
@@ skipping 355 matching lines @@
         }
         suffixes.add(const Link<Uri>().prepend(canonicalUri));
       }
       suffixChainMap[library] = suffixes;
       return;
     }
 
     computeSuffixes(rootLibrary, const Link<Uri>());
   }
 }