Get rid of all the library tags.

lib/src/file.dart

 // Copyright (c) 2014, 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 source_span.file;
-
 import 'dart:math' as math;
 import 'dart:typed_data';
 
 import 'location.dart';
 import 'location_mixin.dart';
 import 'span.dart';
 import 'span_mixin.dart';
 import 'span_with_context.dart';
 
 // Constants to determine end-of-lines.
@@ skipping 332 matching lines @@
       var start = math.min(this._start, other._start);
       var end = math.max(this._end, other._end);
       return new _FileSpan(file, start, end);
     } else {
       var start = math.min(this._start, other.start.offset);
       var end = math.max(this._end, other.end.offset);
       return new _FileSpan(file, start, end);
     }
   }
 }