RFR: 8322174: RISC-V: C2 VectorizedHashCode RVV Version [v18]

[Yuri Gaevsky]

> The patch adds possibility to use RVV instructions for faster vectorizedHashCode calculations on RVV v1.0.0 capable hardware.
> 
> Testing: hotspot/jtreg/compiler/ under QEMU-8.1 with RVV v1.0.0.

Yuri Gaevsky has updated the pull request incrementally with one additional commit since the last revision:

  make powmax calculations scalar; re-use v_tmp for sum reduction operation.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/17413/files
  - new: https://git.openjdk.org/jdk/pull/17413/files/bbcd1ec4..7c5f24aa

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17413&range=17
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17413&range=16-17

  Stats: 7 lines in 1 file changed: 1 ins; 2 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/17413.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17413/head:pull/17413

PR: https://git.openjdk.org/jdk/pull/17413