RFR: 8355570: [s390x] Update -march to z13 generation [v2]

[Lutz Schmidt]

On Thu, 15 May 2025 16:03:51 GMT, Amit Kumar <amitkumar at openjdk.org> wrote:

>> updated march level from z10 to z13.
>> 
>> Testing: tier1 (fastdebug-vm)
>
> Amit Kumar has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision:
> 
>  - Merge branch 'master' into z13
>  - z10 -> z15

This is an overdue change, I agree. 
BUT: I would like to see successful PRODUCT tests. This change enables new  gcc optimizations which fully kick in only in the release build. 
Out of curiosity: do you see any performance gain?

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Changes requested by lucy (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/24869#pullrequestreview-2846141402