RFR: 8371284: GenShen: Avoid unnecessary card marking [v4]

[Aleksey Shipilev]

On Tue, 18 Nov 2025 23:10:42 GMT, Nityanand Rai <duke at openjdk.org> wrote:

>> Exclude young-young, old-old and honor UseCondCardMark in dirty card marking.
>
> Nityanand Rai has updated the pull request incrementally with one additional commit since the last revision:
> 
>   remove UseCondCardMark chnages, to decouple issues fixed

Marked as reviewed by shade (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/28204#pullrequestreview-3481319357