RFR (S): 8233998: New young regions registered too early in collection set

[Thomas Schatzl]

Hi,

   can I have reviews for this change that changes the place in which 
new mutator regions are published in the collection set list?

Previously a new eden region has been published before some data that 
would be read by the young gen sampling thread could be visible.

This change simply does the member updates before adding the regions to 
the collection set.

CR:
https://bugs.openjdk.java.net/browse/JDK-8233998
Webrev:
http://cr.openjdk.java.net/~tschatzl/8233998/webrev/
Testing:
hs-tier1-5 with other similar patches, specjvm2008 specjvm.validation 
with -XX:G1ConcRefinementServiceIntervalMillis=1 (that one causes issues 
quickly if you assert that the remembered sets for regions only grows)

Thanks,
   Thomas