Revert "Delete support for source mirrors"

tests/compiler/dart2js/mirrors/mirrors_test_helper.dart

+// Copyright (c) 2013, 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.
+
+import 'dart:io';
+import 'dart:async';
+
+import 'package:compiler/src/mirrors/source_mirrors.dart';
+import 'package:compiler/src/mirrors/analyze.dart' as source_mirrors;
+import 'package:compiler/src/source_file_provider.dart';
+
+TypeMirror createInstantiation(TypeSourceMirror type,
+                               List<TypeMirror> typeArguments) {
+  return type.createInstantiation(typeArguments);
+}
+
+Future<MirrorSystem> analyze(String test) {
+  Uri repository = Platform.script.resolve('../../../../');
+  Uri testUri = repository.resolve('tests/lib/mirrors/$test');
+  return analyzeUri(testUri);
+}
+
+
+Future<MirrorSystem> analyzeUri(Uri testUri) {
+  Uri repository = Platform.script.resolve('../../../../');
+  Uri libraryRoot = repository.resolve('sdk/');
+  Uri packageRoot = Uri.base.resolve(Platform.packageRoot);
+  var provider = new CompilerSourceFileProvider();
+  var handler = new FormattingDiagnosticHandler(provider);
+  return source_mirrors.analyze(
+      [testUri],
+      libraryRoot,
+      packageRoot,
+      provider,
+      handler);
+}