Migrate first block of tests in standalone to standalone_2

tests/standalone/causal_async_stack_test.dart

Index: tests/standalone/causal_async_stack_test.dart
diff --git a/tests/standalone/causal_async_stack_test.dart b/tests/standalone/causal_async_stack_test.dart
deleted file mode 100644
index faebf3e0e6a5f0e666e3f7fb676557d618069951..0000000000000000000000000000000000000000
--- a/tests/standalone/causal_async_stack_test.dart
+++ /dev/null
@@ -1,29 +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.
-// VMOptions=--causal_async_stacks
-
-import "package:expect/expect.dart";
-
-baz() async {
-  throw "Bad!";
-}
-
-bar() async {
-  await baz();
-}
-
-foo() async {
-  await bar();
-}
-
-main() async {
-  try {
-    await foo();
-  } catch (e, st) {
-    Expect.isTrue(st.toString().contains("baz"));
-    Expect.isTrue(st.toString().contains("bar"));
-    Expect.isTrue(st.toString().contains("foo"));
-    Expect.isTrue(st.toString().contains("main"));
-  }
-}