RFR: 8347343: RISC-V: Unchecked zicntr csr reads [v3]

[Fei Yang]

On Fri, 10 Jan 2025 11:55:54 GMT, Robbin Ehn <rehn at openjdk.org> wrote:

>> Hi, please consider.
>> 
>> The rdinstret/rdcycle/rdtime are really useful and would be great to add in e.g. JFR.
>> But as of now they are not used and zicntr is not yet in hwprobe therefore this patch just make sure they can't be used.
>> 
>> If we need them before hwprobe we can add a flag for manually enabling them.
>> 
>> Sanity tested.
>> 
>> Thanks!
>
> Robbin Ehn has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove header

Looks good.

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Marked as reviewed by fyang (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23003#pullrequestreview-2542257229