Migrate first block of tests in standalone to standalone_2

tests/standalone/dart_developer_env_test.dart

Index: tests/standalone/dart_developer_env_test.dart
diff --git a/tests/standalone/dart_developer_env_test.dart b/tests/standalone/dart_developer_env_test.dart
deleted file mode 100644
index 37e8253e4dd7783a5ca5fe45afe913b9ef479330..0000000000000000000000000000000000000000
--- a/tests/standalone/dart_developer_env_test.dart
+++ /dev/null
@@ -1,10 +0,0 @@
-// Copyright (c) 2017, 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";
-
-main() {
-  Expect
-      .isTrue(const bool.fromEnvironment('dart.developer.causal_async_stacks'));
-}