[jdk21] RFR: 8310656: RISC-V: __builtin___clear_cache can fail silently.

[Robbin Ehn]

Hi all,

This pull request contains a backport of commit [faf1b822](https://github.com/openjdk/jdk/commit/faf1b822d03b726413d77a2b247dfbbf4db7d57e) from the [openjdk/jdk](https://git.openjdk.org/jdk) repository.

The commit being backported was authored by Robbin Ehn on 2 Jul 2023 and was reviewed by Ludovic Henry, Thomas Stuefe and Fei Yang.

Thanks!

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Commit messages:
 - Backport faf1b822d03b726413d77a2b247dfbbf4db7d57e

Changes: https://git.openjdk.org/jdk21/pull/90/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21&pr=90&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8310656
  Stats: 121 lines in 3 files changed: 116 ins; 1 del; 4 mod
  Patch: https://git.openjdk.org/jdk21/pull/90.diff
  Fetch: git fetch https://git.openjdk.org/jdk21.git pull/90/head:pull/90

PR: https://git.openjdk.org/jdk21/pull/90