RFR: 8351565: Implement JEP 502: Stable Values (Preview) [v21]

[Per Minborg]

On Mon, 31 Mar 2025 13:32:56 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> Implement JEP 502.
>> 
>> The PR passes tier1-tier3 tests.
>
> Per Minborg has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Finish and clean up benchmarks

Here is new result of the new `MethodHandle` benchmark:


Benchmark                             Mode  Cnt  Score   Error  Units
StableMethodHandleBenchmark.finalMh   avgt   10  0.809 ? 0.120  ns/op
StableMethodHandleBenchmark.mh        avgt   10  3.509 ? 0.199  ns/op
StableMethodHandleBenchmark.stableMh  avgt   10  0.762 ? 0.050  ns/op

-------------

PR Comment: https://git.openjdk.org/jdk/pull/23972#issuecomment-2766694309