RFR: 8371284: GenShen: Avoid unnecessary card marking

[Nityanand Rai]

Exclude young-young, old-old and honor UseCondCardMark in dirty card marking.

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Commit messages:
 - clean whitespace
 - minor cleanup
 - Merge branch 'openjdk:master' into 8371284
 - exclude young-yong, old-old and honor UseCondCardMark in dirty card marking

Changes: https://git.openjdk.org/jdk/pull/28204/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28204&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8371284
  Stats: 21 lines in 1 file changed: 20 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/28204.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28204/head:pull/28204

PR: https://git.openjdk.org/jdk/pull/28204