[riscv-port] RFR: 8283364: riscv: Intrinsify countPositives [v2]

[Fei Yang]

On Mon, 21 Mar 2022 02:55:43 GMT, Feilong Jiang <fjiang at openjdk.org> wrote:

>> [JDK-8281146](https://bugs.openjdk.java.net/browse/JDK-8281146) replaces `StringCoding.hasNegatives` with `countPositives` and introduces `Op_CountPositives`, which can be intrinsified on riscv port.
>> 
>> New added test test/hotspot/jtreg/compiler/intrinsics/string/TestCountPositives.java passed on QEMU with RVV enabled.
>> 
>> hotspot and jdk tier1 tests on QEMU with UseRVV enabled are passed without new failures.
>
> Feilong Jiang has updated the pull request incrementally with one additional commit since the last revision:
> 
>   instruct definition adjustment

Thanks for reworking this intrinsic. Looks good.

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Marked as reviewed by fyang (Lead).

PR: https://git.openjdk.java.net/riscv-port/pull/67