RFR(M): Backport of changes for 7176479 to hs24

[John Cuthbertson]

Hi Everyone,

The exported changeset for 7176479 from hsx25 did not apply cleanly to 
hsx24 - mostly due to some NPG changes. Hence, can I please have a 
couple of volunteers look over the backport? The backport webrev can be 
found at: http://cr.openjdk.java.net/~johnc/7176479-hsx24-backport/webrev.0/

Three files had rejected chunks: concurrentG1Refine.hpp, 
g1GCPhaseTimes.hpp, and g1RemSet.cpp. The fix-ups to 
concurrentG1Refine.hpp and g1GCPhaseTimes.hpp were trivial; g1RemSet.cpp 
required a bit more effort and that is where I'd like people to concentrate.

Testing: jprt and GCOld.

Thanks,

JohnC