Update imports to use package:compiler and package:try.

dart/tests/compiler/dart2js/bad_loop_test.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 'package:expect/expect.dart';
 import 'memory_source_file_helper.dart';
 import "package:async_helper/async_helper.dart";
 
-import '../../../sdk/lib/_internal/compiler/compiler.dart'
+import 'package:compiler/compiler.dart'
        show Diagnostic;
 
 main() {
   Uri script = currentDirectory.resolveUri(Platform.script);
   Uri libraryRoot = script.resolve('../../../sdk/');
   Uri packageRoot = script.resolve('./packages/');
 
   var provider = new MemorySourceFileProvider(MEMORY_SOURCE_FILES);
   int warningCount = 0;
   int errorCount = 0;
@@ skipping 38 matching lines @@
   }
 
   for ((){}() in []) {
   }
 
   for (1 in []) {
   }
 }
 """
 };