RFR: 8311074: RISC-V: Fix -Wconversion warnings in some code header files [v2]

[Coleen Phillimore]

On Thu, 29 Jun 2023 02:05:04 GMT, Gui Cao <gcao at openjdk.org> wrote:

>> Hi, refer to the modification of aarch64 in https://github.com/openjdk/jdk/pull/14675 , here is the riscv version, before this PR has the same -Wconversion warnings as aarch64, after this this PR the -Wconversion warnings has been eliminated.
>> Please take a look and have some reviews. Thanks a lot.
>> 
>> ## Testing:
>> - [x] Tier1 tests (release)
>
> Gui Cao has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Keep the surrounding spaces for /

Looks good.  Sorry I guess I could have done these also.  Thank you.

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Marked as reviewed by coleenp (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/14702#pullrequestreview-1505178669