RFR: 8342579: RISC-V: C2: Cleanup effect of killing flag register for call instructs

[Robbin Ehn]

On Fri, 18 Oct 2024 02:24:16 GMT, Fei Yang <fyang at openjdk.org> wrote:

> Previously found and discussed at: https://github.com/openjdk/jdk/pull/21406#discussion_r1803232561
> For C2 call nodes, it's not necessary to add effect listing flag register as being killed.
> This cleans them up and thus aligns with other CPU platforms.
> 
> Testing on linux-riscv64:
> - [x] Tier1 (release build)

Thank you, looks good!

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Marked as reviewed by rehn (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/21576#pullrequestreview-2377150885