Code Review 6562203: Thread doesn't terminate immediately if it was stopped before start

[Chris Hegarty]

David,

Since your changes for CR 6566340 "Restore use of stillborn flag to 
signify a thread that was stopped before it started", are now promoted 
in hs21.0-b01, I would like to proceed with this clean up in the 
libraries. Basically reverse out the changes that were made by CR 
4519200, in JDK6. Stop before start will now be correctly handled solely 
by the VM.

Also, some minor changes to an existing StopBeforeStart regression test.

http://cr.openjdk.java.net/~chegar/6562203/webrev.00/webrev/

Thanks,
-Chris.