merge fasta.Keyword into analyzer.Keyword

pkg/front_end/lib/src/fasta/scanner/array_based_scanner.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.array_based_scanner;
 
 import 'error_token.dart' show ErrorToken, UnmatchedToken;
 
-import 'keyword.dart' show Keyword;
+import '../../scanner/token.dart' show Keyword;
 
 import 'precedence.dart' show PrecedenceInfo;
 
 import 'token.dart'
     show
         BeginGroupToken,
         KeywordToken,
         StringToken,
         SymbolToken,
         SyntheticSymbolToken,
@@ skipping 280 matching lines @@
     //      |
     //     next
     //      v
     //     EOF
     PrecedenceInfo info = closeBraceInfoFor(begin);
     appendToken(new SyntheticSymbolToken(info, tokenStart));
     begin.endGroup = tail;
     appendErrorToken(new UnmatchedToken(begin));
   }
 }