8228388: Add information about dirty/skipped card for Merge HCC in G1 log Summary: Collect and print informatio about the number of processed cards during the Merge HCC phase to improve log output. Reviewed-by: kbarrett, sangheki

/build/
/dist/
/.idea/
nbproject/private/
/webrev
/.src-rev
/.jib/
.DS_Store
.metadata/
.recommenders/
test/nashorn/script/external
test/nashorn/lib
NashornProfile.txt
**/JTreport/**
**/JTwork/**