[vm/cocurrency] Add simple spawn function test and test with/without isolate groups

This fixes also an issue when running without isolate groups.

Issue #36097

Change-Id: I0fb64b3f2b755ccab4c36c6a0fafee7edff239cf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/114204
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>

Author: mkustermann

runtime/bin/main.cc

@@ -662,11 +662,11 @@ static Dart_Isolate CreateIsolateGroupAndSetupHelper(
   }
 
   if (flags->copy_parent_code && callback_data) {
-    IsolateGroupData* parent_isolate_data =
-        reinterpret_cast<IsolateGroupData*>(callback_data);
-    parent_kernel_buffer = parent_isolate_data->kernel_buffer();
+    auto parent_isolate_group_data =
+        reinterpret_cast<IsolateData*>(callback_data)->isolate_group_data();
+    parent_kernel_buffer = parent_isolate_group_data->kernel_buffer();
     kernel_buffer = parent_kernel_buffer.get();
-    kernel_buffer_size = parent_isolate_data->kernel_buffer_size();
+    kernel_buffer_size = parent_isolate_group_data->kernel_buffer_size();
   }
 
   if (kernel_buffer == NULL && !isolate_run_app_snapshot) {

runtime/tests/vm/dart/isolates/spawn_function_test.dart

@@ -0,0 +1,32 @@
+// Copyright (c) 2019, 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=--enable-isolate-groups
+// VMOptions=--no-enable-isolate-groups
+
+import 'dart:isolate';
+import 'dart:async';
+
+import 'package:expect/expect.dart';
+
+void isolateEntry(args) {
+  final SendPort sendPort = args;
+  sendPort.send('hello world');
+}
+
+main() async {
+  final port = ReceivePort();
+  final exitPort = ReceivePort();
+
+  await Isolate.spawn(isolateEntry, port.sendPort, onExit: exitPort.sendPort);
+
+  final messages = StreamIterator(port);
+  Expect.isTrue(await messages.moveNext());
+  Expect.equals('hello world', messages.current);
+  await messages.cancel();
+
+  final exit = StreamIterator(exitPort);
+  Expect.isTrue(await exit.moveNext());
+  await exit.cancel();
+}