Request for review (XS): 7106751 G1: gc/gctests/nativeGC03 crashes VM with SIGSEGV

[Bengt Rutisson]

Hi all,

Could I have a couple of reviews for this small fix?

http://cr.openjdk.java.net/~brutisso/7106751/webrev.01/

Fixes an issue found during PIT testing of hs23-b04:

7106751 G1: gc/gctests/nativeGC03 crashes VM with SIGSEGV
http://monaco.us.oracle.com/detail.jsf?cr=7106751

We use the worker id:s of ConcurrentRefineThreads to index a 
datastructure that is only set up for GC workers.

Testing: JPRT. Also ran 7000 iterations on the failing machine 
(intelsdv36). Without my fix debug builds would fail every 20 iterations 
or so.

Thanks,
Bengt