Add a JDK 15 test for sealed classes

Bug: 169692487
Bug: 169645291
Change-Id: I5fb0b015df67b93760ef7107fda1aa76696d3760
diff --git a/src/test/examplesJava15/sealed/Main.java b/src/test/examplesJava15/sealed/Main.java
new file mode 100644
index 0000000..f163a21
--- /dev/null
+++ b/src/test/examplesJava15/sealed/Main.java
@@ -0,0 +1,13 @@
+// Copyright (c) 2020, the R8 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.
+
+package sealed;
+
+public class Main {
+
+  public static void main(String[] args) {
+    new R8Compiler().run();
+    new D8Compiler().run();
+  }
+}