RFR: 8374518: C1: Remove dead LinearScanStatistic::Counter::counter_fpu_stack

[Christian Hagedorn]

On Mon, 5 Jan 2026 13:42:30 GMT, Tobias Hartmann <thartmann at openjdk.org> wrote:

>> The usages of `LinearScanStatistic::Counter::counter_fpu_stack` were removed with [JDK-8351156](https://bugs.openjdk.org/browse/JDK-8351156) when the FPU stack support was removed. But the definition in the `Counter` enum was missed to clean up. When now printing the counters with `-XX:+CountLinearScan -XX:+CITime`, we reach a `ShouldNotReach` in `LinearScanStatistic::counter_name()` for `Counter::counter_fpu_stack` because there is no longer an entry there - it's dead.
>> 
>> I added a simple hello world sanity test that runs with `-XX:+CountLinearScan -XX:+CITime`.
>> 
>> Thanks,
>> Christian
>
> Looks good and trivial.

Thanks for your reviews @TobiHartmann and @TheRealMDoerr! I will wait until some sanity testing passed before integration.

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PR Comment: https://git.openjdk.org/jdk/pull/29037#issuecomment-3710491827