code review request: Test case for JDK-7198904 TreeMap.clone issue

[David Buck]

Hi!

This is a review request to add only the test case for the following 
OracleJDK issue:

[ 7198904 : (alt-rt) TreeMap.clone is broken ]
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7198904

The issue (root cause) is not in OpenJDK (i.e. the problem was OracleJDK 
specific), but the test case is valid for both so it should go into 
OpenJDK so we can prevent a similar issue from ever happening in both 
releases moving forward.

webrev:

[ Code Review for jdk ]
http://cr.openjdk.java.net/~dbuck/7198904/webrev.00/

The OracleJDK fix (closed source) is ready and has already passed code 
review. I intend to push both the OracleJDK fix and this test case into 
their respective repositories at the same time once this review is done.

Regards,
-Buck