[jdk21u] RFR: 8316592: RISC-V: implement poly1305 intrinsic [v2]

[ArsenyBochkarev]

> Backport for `_poly1305_processBlocks` intrinsic. Review here: https://github.com/openjdk/jdk/pull/16417. I re-run the tier1 tests and `test/jdk/com/sun/crypto/provider/Cipher/ChaCha20/unittest/Poly1305UnitTestDriver.java` test specifically just as a sanity checks and they're ok.

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

  Empty commit

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Changes:
  - all: https://git.openjdk.org/jdk21u/pull/390/files
  - new: https://git.openjdk.org/jdk21u/pull/390/files/45ff1f2f..59789f83

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk21u&pr=390&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk21u&pr=390&range=00-01

  Stats: 0 lines in 0 files changed: 0 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u/pull/390.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/390/head:pull/390

PR: https://git.openjdk.org/jdk21u/pull/390