Separate is_debuggable and is_visible again. The outer async functions

tests/language/async_or_generator_return_type_stacktrace_test.dart

Index: tests/language/async_or_generator_return_type_stacktrace_test.dart
diff --git a/tests/language/async_or_generator_return_type_stacktrace_test.dart b/tests/language/async_or_generator_return_type_stacktrace_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..1fa3d9378e4697437f910b9b007b46df615a6ad5
--- /dev/null
+++ b/tests/language/async_or_generator_return_type_stacktrace_test.dart
@@ -0,0 +1,35 @@
+// Copyright (c) 2015, 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";
+
+void badReturnTypeAsync() async {}  /// 01: static type warning
+void badReturnTypeAsyncStar() async* {}  /// 02: static type warning
+void badReturnTypeSyncStar() sync* {}  /// 03: static type warning
+
+main() {
+  try {
+    badReturnTypeAsync();  /// 01: continued
+  } catch(e, st) {
+    Expect.isTrue(e is TypeError, "wrong exception type");
+    Expect.isTrue(st.toString().contains("badReturnTypeAsync"),
+                  "missing frame");
+  }
+
+  try {
+    badReturnTypeAsyncStar();  /// 02: continued
+  } catch(e, st) {
+    Expect.isTrue(e is TypeError, "wrong exception type");
+    Expect.isTrue(st.toString().contains("badReturnTypeAsyncStar"),
+                  "missing frame");
+  }
+
+  try {
+    badReturnTypeSyncStar();  /// 03: continued
+  } catch(e, st) {
+    Expect.isTrue(e is TypeError, "wrong exception type");
+    Expect.isTrue(st.toString().contains("badReturnTypeSyncStar"),
+                  "missing frame");
+  }
+}