RFR: 8365262: [IR-Framework] Add simple way to add cross-product of flags [v9]

[Emanuel Peter]

On Tue, 26 Aug 2025 13:23:57 GMT, Manuel Hässig <mhaessig at openjdk.org> wrote:

>> This PR adds the `TestFramework::addCrossProductScenarios` method to enable more ergonomic testing of the combination of all flag combinations. To illustrate its use, I also converted one test to use the new cross product functionality.
>> 
>> Testing:
>>  - [x] Github Actions
>>  - [x] tier1,tier2 plus some internal testing on Oracle supported platforms
>
> Manuel Hässig has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Review

Thanks for all the updates! It's going to make the tests just a little nicer 😊

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Marked as reviewed by epeter (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/26762#pullrequestreview-3159116771