RFR(S): Backport of changes for 8015237 to hs24

[John Cuthbertson]

Hi Everyone,

The hs25 changes for 8015237 did not apply cleanly to hs24 (no surprise 
there) so can I have a couple of volunteers look over these backported 
changes?

The backported changes including Chris' comments about changing the name 
of StringTable::_par_claimed_index can be found at: 
http://cr.openjdk.java.net/~johnc/8015237-hsx24-backport/webrev.0/

The original hsx25 webrev (minus Chris' comments) can be found at: 
http://cr.openjdk.java.net/~johnc/8015237/webrev.1/

Testing: GC testsuite with G1 and CMS with ParallelGCThreads=4; jprt.

Thanks,

JohnC