Get deploy tests working on Windows.

sdk/lib/_internal/pub/test/deploy/reports_dart_parse_errors_test.dart

Index: sdk/lib/_internal/pub/test/deploy/reports_dart_parse_errors_test.dart
diff --git a/sdk/lib/_internal/pub/test/deploy/reports_dart_parse_errors_test.dart b/sdk/lib/_internal/pub/test/deploy/reports_dart_parse_errors_test.dart
index 6875a43e7032d4497e7593ea15e64d91950b988f..89ad7ad88335a48c521c9070dc8af84e329e9068 100644
--- a/sdk/lib/_internal/pub/test/deploy/reports_dart_parse_errors_test.dart
+++ b/sdk/lib/_internal/pub/test/deploy/reports_dart_parse_errors_test.dart
@@ -2,6 +2,7 @@
 // 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:pathos/path.dart' as path;
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../descriptor.dart' as d;
@@ -29,8 +30,8 @@ main() {
             multiLine: true),
         output: '''
 Finding entrypoints...
-Copying   web/ => deploy/
-''',
+Copying   web| => deploy|
+'''.replaceAll('|', path.separator),
         exitCode: 0);
 
     d.dir(appPath, [