Remove library tags, they aren't needed

lib/src/compiler.dart

 // Copyright (c) 2015, 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.
 
 /// Command line tool to run the checker on a Dart program.
-library dev_compiler.src.compiler;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert' show JSON;
 import 'dart:math' as math;
 import 'dart:io';
 
 import 'package:analyzer/src/generated/ast.dart' show CompilationUnit;
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart'
@@ skipping 518 matching lines @@
   var files = [
     'harmony_feature_check.js',
     'dart_library.js',
     'dart/_runtime.js',
   ];
   files.addAll(corelibOrder.map(coreToFile));
   return files;
 }();
 
 final _log = new Logger('dev_compiler.src.compiler');