RFR: 8164805: Fail to create a MR modular JAR with a versioned entry in base-versioned empty package

[Steve Drach]

Hi,

Please review the following changeset.  This fix allows jar tool to add a new public class in a versioned directory in a modular multi-release jar file if the class is in a concealed package. When this event takes place, a warning message is emitted saying that placing this jar on a class path will result in an incompatible public interface, the jar file does not meet the single api rule of a multi-release jar file.  As before, adding a new public class in a versioned directory of a multi-release jar file (not a modular jar file) will result in an error.

issue: https://bugs.openjdk.java.net/browse/JDK-8164805 <https://bugs.openjdk.java.net/browse/JDK-8164805>

webrev: http://cr.openjdk.java.net/~sdrach/8164805/webrev.00/ <http://cr.openjdk.java.net/~sdrach/8164805/webrev.00/>

Thanks,
Steve