RFR: 8340643: RISC-V: Small refactoring for sub/subw macro-assembler routines

[Fei Yang]

On Mon, 23 Sep 2024 12:39:07 GMT, Gui Cao <gcao at openjdk.org> wrote:

> Hi, please help review that, small refactoring for sub/subw macro-assembler routines.
> 
> ### Testing
> - [x] Run tier1 tests on SOPHON SG2042 (release)

Good to see duplicate code removed. Thanks.

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Marked as reviewed by fyang (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/21135#pullrequestreview-2323853990