RFR 8246337: Add more JVM tests for sealed classes

[Harold Seigel]

Hi,

Please review this change to add more JVM tests for sealed classes.  
With this change there are now the following set of tests for both 
sealed classes and sealed interfaces.

 1. Successful tests when both the subclass and its sealed super type
    are in the same module and package and subclass is listed on its
    sealed type's permits list.
 2. Successful tests when both the subclass and its sealed super type
    are in the same module, different package, and the subclass is open
    and is listed on its sealed type's permits list.
 3. Error tests for when the subclass and its sealed super type are in
    different modules and the subclass is listed on its sealed type's
    permits list.
 4. Error tests for when the subclass and its sealed super type are in
    the same module, but different packages, and the subclass is not
    open and the subclass is listed on its sealed type's permit list.
 5. Error tests for when the subclass and its sealed super type are in
    the same module and package but the subclass is not listed on its
    sealed type's permits list.

Open Webrev: 
http://cr.openjdk.java.net/~hseigel/bug_8246337/webrev/index.html

JBS Bug: https://bugs.openjdk.java.net/browse/JDK-8246337

The new and modified tests were tested on Linux-x64, Linux-aarch64, 
Windows, and Mac OS X using Mach5.

Thanks, Harold