Copy dart2js source into pkg/compiler

pkg/compiler/lib/src/mirrors/analyze.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 dart2js.source_mirrors.analyze;
 
 import 'dart:async';
 
 import 'source_mirrors.dart';
 import 'dart2js_mirrors.dart' show Dart2JsMirrorSystem;
@@ skipping 46 matching lines @@
                                            const {});
   compiler.librariesToAnalyzeWhenRun = libraries;
   return compiler.run(null).then((bool success) {
     if (success && !compilationFailed) {
       return new Dart2JsMirrorSystem(compiler);
     } else {
       throw new StateError('Failed to create mirror system.');
     }
   });
 }