RFR (XXS): 8198546: [Redo] JDK-8196883 G1RemSet::refine_card_concurrently doesn't need to check for cards in collection set

[Thomas Schatzl]

Hi all,

  can I have reviews for this redo of an earlier change that has been
accidentally pushed to the jdk10 repo, backed out there, and everything
only recently been merged with jdk 11?

The change itself is unmodified.

CR:
https://bugs.openjdk.java.net/browse/JDK-8198546
Webrev:
http://cr.openjdk.java.net/~tschatzl/8198546/webrev/
Testing:
local compilation

Thanks,
  Thomas