Improve recovery from compile-time errors.

pkg/analyzer/test/generated/parser_fasta_test.dart

 // Copyright (c) 2017, 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.
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart' as analyzer;
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/fasta/ast_builder.dart';
 import 'package:analyzer/src/fasta/element_store.dart';
@@ skipping 754 matching lines @@
  */
 class KernelLibraryBuilderProxy implements KernelLibraryBuilder {
   @override
   final uri = Uri.parse('file:///test.dart');
 
   @override
   Uri get fileUri => uri;
 
   @override
   void addCompileTimeError(int charOffset, Object message,
-      {Uri fileUri, bool silent: false}) {
+      {Uri fileUri, bool silent: false, bool wasHandled: false}) {
     fail('$message');
   }
 
   noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }
 
 /**
  * Proxy implementation of the analyzer parser, implemented in terms of the
  * Fasta parser.
  *
@@ skipping 210 matching lines @@
   }
 
   @override
   @failingTest
   void test_parsePartOfDirective_uri() {
     // TODO(paulberry,ahe): URIs in "part of" declarations are not supported by
     // Fasta.
     super.test_parsePartOfDirective_uri();
   }
 }