Migrate first block of tests in standalone to standalone_2

tests/standalone_2/io/addlatexhash_test.dart

 #!/usr/bin/env dart
 // Copyright (c) 2014, 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.
 
 // testing ../../../tools/addlatexhash.dart
 
 import 'dart:io';
 import 'package:path/path.dart' as path;
 import '../../../tools/addlatexhash.dart';
@@ skipping 55 matching lines @@
 }
 
 // Check that the hash values of paragraphs in the specially prepared
 // LaTeX source 'addlatexhash_test_src.tex' are identical in groups
 // of eight (so we get 8 identical hash values, then another hash
 // value 8 times, etc.)
 testSameHash(String tmpDirPath) {
   // file names/paths for file containing groups of 8 variants of a paragraph
   const par8timesName = "addlatexhash_test_src";
   const par8timesFileName = "$par8timesName.tex";
-  final par8timesDirPath = path.join(dartRootDir, "tests", "standalone", "io");
+  final par8timesDirPath =
+      path.join(dartRootDir, "tests", "standalone_2", "io");
   final par8timesPath = path.join(par8timesDirPath, par8timesFileName);
   final tmpPar8timesPath = path.join(tmpDirPath, par8timesFileName);
 
   // file names paths for output
   final hashName = par8timesName + "-hash";
   final hashFileName = "$hashName.tex";
   final hashPath = path.join(tmpDirPath, hashFileName);
   final listName = par8timesName + "-list";
   final listFileName = "$listName.txt";
   final listPath = path.join(tmpDirPath, listFileName);
@@ skipping 124 matching lines @@
 main([args]) {
   testCutMatch();
   testSisp();
 
   runWithTempDir(testSameHash);
   // latex and dvi2tty are not installed in the standard test environment
   if (args.length > 0 && args[0] == "local") {
     runWithTempDir(testSameDVI);
   }
 }