RFR: 8349632: RISC-V: Add Zfa fminm/fmaxm [v4]

[Fei Yang]

On Wed, 12 Mar 2025 03:45:36 GMT, Anjian Wen <duke at openjdk.org> wrote:

>> Add RISCV zfa extension fminm/fmaxm
>> This two new Floating-point instructions can deal with NaN input directly, which can decrease instructions when calculate min or max
>
> Anjian Wen has updated the pull request incrementally with one additional commit since the last revision:
> 
>   delete useless comment

Looks good. hotspot:tier1 test good using qemu-system with UseZfa enabled by default.
BTW: Similar thing could be done for the float16 variant after https://github.com/openjdk/jdk/pull/23844 is merged.

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Marked as reviewed by fyang (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23509#pullrequestreview-2680156671