RFR: 8361449: RISC-V: Code cleanup for native call [v2]

[Dingli Zhang]

On Mon, 14 Jul 2025 07:11:34 GMT, Fei Yang <fyang at openjdk.org> wrote:

>>>  it is partially synchronized with [JDK-8321509](https://bugs.openjdk.org/browse/JDK-8321509), mainly 4 and 6 [here](https://github.com/openjdk/jdk/pull/19796#issuecomment-2188094970). 
>> 
>> As you mentioned in PR, this is just cleanup. Should we add this code in a separate PR?
>
> I agree with @feilongjiang that we should keep this a cleanup change which shouldn't modify the original logic.

Thanks all for the review! 
I will only keep the clean up part and revert the rest of the changes.

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PR Review Comment: https://git.openjdk.org/jdk/pull/26150#discussion_r2204025695