Move testing.json and status files to more natural locations.

pkg/front_end/test/fasta/scanner/scanner_suite.dart

 // Copyright (c) 2016, 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.md file.
 
 import 'package:testing/testing.dart';
 
 import 'package:front_end/src/fasta/testing/scanner_chain.dart';
 
 Future<ChainContext> createContext(
     Chain suite, Map<String, String> environment) async {
   return new ScannerContext();
 }
 
 class ScannerContext extends ChainContext {
   final List<Step> steps = const <Step>[
     const Read(),
     const Scan(),
   ];
 }
 
 main(List<String> arguments) =>
-    runMe(arguments, createContext, "../testing.json");
+    runMe(arguments, createContext, "../../../testing.json");