RFR (7xS): 8071280: Specialize HeapRegion::oops_on_card_seq_iterate_careful() for use during concurrent refinement and updating the rset

[Thomas Schatzl]

Hi all,

  Erik Helin had a few comments regarding naming etc. that this new
webrev incorporates:

Webrevs:
http://cr.openjdk.java.net/~tschatzl/8071280/webrev.2_to_3/ (diff)
http://cr.openjdk.java.net/~tschatzl/8071280/webrev.3/ (full)

Thanks,
  Thomas