RFR: 8307758: RISC-V: Improve bit test code introduced by JDK-8291555

[Fei Yang]

On Tue, 9 May 2023 08:14:30 GMT, Feilong Jiang <fjiang at openjdk.org> wrote:

> [JDK-8291555](https://bugs.openjdk.org/browse/JDK-8291555) introduced some single-bit tests that use `andi`, we can replace it with `test_bit` to avoid using the temp register when UseZbs is enabled.
> 
> Testing:
> - [x] tier1-tier3 on Unmatched board (release build)

Looks good. Thanks.

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Marked as reviewed by fyang (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/13882#pullrequestreview-1419736700