Port parser and scanner fixes from rasta branch.

pkg/front_end/lib/src/fasta/scanner/keyword.dart

 // Copyright (c) 2011, 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 fasta.scanner.keywords;
 
 import 'characters.dart' show
     $a;
 
 import 'precedence.dart' show
@@ skipping 56 matching lines @@
     const Keyword("get", isBuiltIn: true),
     const Keyword("implements", isBuiltIn: true),
     const Keyword("import", isBuiltIn: true),
     const Keyword("library", isBuiltIn: true),
     const Keyword("operator", isBuiltIn: true),
     const Keyword("part", isBuiltIn: true),
     const Keyword("set", isBuiltIn: true),
     const Keyword("static", isBuiltIn: true),
     const Keyword("typedef", isBuiltIn: true),
 
+    const Keyword("async", isPseudo: true),
+    const Keyword("await", isPseudo: true),
+    const Keyword("deferred", isPseudo: true),
     const Keyword("hide", isPseudo: true),
     const Keyword("native", isPseudo: true),
     const Keyword("of", isPseudo: true),
     const Keyword("on", isPseudo: true),
+    const Keyword("patch", isPseudo: true),
     const Keyword("show", isPseudo: true),
     const Keyword("source", isPseudo: true),
-    const Keyword("deferred", isPseudo: true),
-    const Keyword("async", isPseudo: true),
     const Keyword("sync", isPseudo: true),
-    const Keyword("await", isPseudo: true),
     const Keyword("yield", isPseudo: true),
   ];
 
   final String syntax;
   final bool isPseudo;
   final bool isBuiltIn;
   final PrecedenceInfo info;
 
   static Map<String, Keyword> _keywords;
   static Map<String, Keyword> get keywords {
@@ skipping 115 matching lines @@
 /**
  * A state that has no outgoing transitions.
  */
 class LeafKeywordState extends KeywordState {
   LeafKeywordState(String syntax) : super(Keyword.keywords[syntax]);
 
   KeywordState next(int c) => null;
 
   String toString() => keyword.syntax;
 }