RFR: 8338428: Add logging of final VM flags while setting properties [v6]

[Roger Riggs]

On Fri, 17 Jan 2025 18:50:22 GMT, Leonid Mesnik <lmesnik at openjdk.org> wrote:

>> Some VM flags might depend on the environment and it makes sense to log final flags so it is possible to get their value when investigating failures.
>> 
>> I added them to VMProps, so it is always dump final flags before running tests using "-XX:+PrintFlagsFinal".
>> 
>> Update:
>> There were intermittent compilation failures when I tried to use classes from testlibrary, so I rewrtite the code without them.
>
> Leonid Mesnik has updated the pull request incrementally with one additional commit since the last revision:
> 
>   updated flags

lgtm

Got it, I've resolved my mis-understanding of the properties being changed to the narrow use of invoking the initial VMProps to determine the supported properties of the VM under test.

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Marked as reviewed by rriggs (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23054#pullrequestreview-2565158818
PR Comment: https://git.openjdk.org/jdk/pull/23054#issuecomment-2605213324