Port parser and scanner fixes from rasta branch.

tests/compiler/dart2js/message_kind_helper.dart

 // Copyright (c) 2013, 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.test.message_kind_helper;
 
 import 'package:expect/expect.dart';
 import 'dart:async';
 
 import 'package:compiler/src/commandline_options.dart';
 import 'package:compiler/src/compiler.dart' show Compiler;
 import 'package:compiler/src/diagnostics/messages.dart'
     show MessageKind, MessageTemplate;
 import 'package:compiler/compiler_new.dart' show Diagnostic;
 
 import 'memory_compiler.dart';
 
 const String ESCAPE_REGEXP = r'[[\]{}()*+?.\\^$|]';
 
 /// Most examples generate a single diagnostic.
 /// Add an exception here if a single diagnostic cannot be produced.
 /// However, consider that a single concise diagnostic is easier to understand,
 /// so try to change error reporting logic before adding an exception.
 final Set<MessageKind> kindsWithExtraMessages = new Set<MessageKind>.from([
-  // If you add something here, please file a *new* bug report.

[ahe, 2017/01/28 00:33:33]

Given that we're moving away from this front-end, I think we don't need to worry
about this anymore.

[Johnni Winther, 2017/01/30 09:04:39]

Acknowledged.

   // See http://dartbug.com/18361:
   MessageKind.CANNOT_EXTEND_MALFORMED,
   MessageKind.CANNOT_IMPLEMENT_MALFORMED,
   MessageKind.CANNOT_MIXIN,
   MessageKind.CANNOT_MIXIN_MALFORMED,
   MessageKind.CANNOT_INSTANTIATE_ENUM,
   MessageKind.CYCLIC_TYPEDEF_ONE,
   MessageKind.DUPLICATE_DEFINITION,
   MessageKind.EQUAL_MAP_ENTRY_KEY,
   MessageKind.FINAL_FUNCTION_TYPE_PARAMETER,
   MessageKind.FORMAL_DECLARED_CONST,
   MessageKind.FORMAL_DECLARED_STATIC,
   MessageKind.FUNCTION_TYPE_FORMAL_WITH_DEFAULT,
   MessageKind.HIDDEN_IMPLICIT_IMPORT,
   MessageKind.HIDDEN_IMPORT,
   MessageKind.INHERIT_GETTER_AND_METHOD,
   MessageKind.UNIMPLEMENTED_METHOD,
   MessageKind.UNIMPLEMENTED_METHOD_ONE,
   MessageKind.VAR_FUNCTION_TYPE_PARAMETER,
+  MessageKind.UNMATCHED_TOKEN,

[ahe, 2017/01/28 00:33:33]

The message is repeated: first during diet parsing, then when parsing the body
again.

I have fixed this problem before (in rasta), but I don't think it matters now.

 ]);
 
 /// Most messages can be tested without causing a fatal error. Add an exception
 /// here if a fatal error is unavoidable and leads to pending classes.
 /// Try to avoid adding exceptions here; a fatal error causes the compiler to
 /// stop before analyzing all input, and it isn't safe to reuse it.
 final Set<MessageKind> kindsWithPendingClasses = new Set<MessageKind>.from([
   // If you add something here, please file a *new* bug report.
 ]);
 
@@ skipping 86 matching lines @@
           .isTrue(!pendingStuff || kindsWithPendingClasses.contains(template));
 
       if (!pendingStuff) {
         // If there is pending stuff, or the compiler was cancelled, we
         // shouldn't reuse the compiler.
         cachedCompiler = compiler;
       }
     });
   }).then((_) => cachedCompiler);
 }