fasta scanner recovery and error code translation improvements

pkg/front_end/lib/src/fasta/scanner/abstract_scanner.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 fasta.scanner.abstract_scanner;
 
 import 'dart:collection' show ListMixin;
 
 import 'dart:typed_data' show Uint16List, Uint32List;
 
@@ skipping 24 matching lines @@
    */
   int tokenStart = -1;
 
   /**
    * A pointer to the token stream created by this scanner. The first token
    * is a special token and not part of the source file. This is an
    * implementation detail to avoids special cases in the scanner. This token
    * is not exposed to clients of the scanner, which are expected to invoke
    * [firstToken] to access the token stream.
    */
-  final Token tokens = new SymbolToken(EOF_INFO, -1);
+  final Token tokens = new SymbolToken.eof(-1);
 
   /**
    * A pointer to the last scanned token.
    */
   Token tail;
 
   /**
    * A pointer to the stream of comment tokens created by this scanner
    * before they are assigned to the [Token] precedingComments field
    * of a non-comment token. A value of `null` indicates no comment tokens.
@@ skipping 1192 matching lines @@
       switchToUint32(newLength);
     }
   }
 
   void switchToUint32(int newLength) {
     final newArray = new Uint32List(newLength);
     newArray.setRange(0, arrayLength, array);
     array = newArray;
   }
 }