RFR: 8010514: G1: Concurrent mode failure tracing event

[Kevin Walls]

Hi,

I'd like to get a review on this G1 event for hs24.  It offers a similar 
warning to the concurrent mode failure in CMS when the concurrent part 
of the collection (concurrent mark here in G1) aborts (and is an event 
fairly equivalent to seeing "concurrent-mark-abort" on the text log).

http://cr.openjdk.java.net/~kevinw/8010514/webrev/

Thanks
Kevin