[jdk17u-dev] RFR: 8316743: RISC-V: Change UseVectorizedMismatchIntrinsic option result to warning

[Fei Yang]

VectorizedMismatch intrinsic is not implemented on linux-riscv platform. Backport this fix to avoid JVM crash when user specified JVM options -XX:+UnlockDiagnosticVMOptions -XX:+UseVectorizedMismatchIntrinsic on the command line. RISC-V only change, risk is low.

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Commit messages:
 - Backport 750da0012931656cfd55f3e67c3f49ad7363ab8e

Changes: https://git.openjdk.org/jdk17u-dev/pull/1823/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1823&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8316743
  Stats: 6 lines in 2 files changed: 5 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1823.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/1823/head:pull/1823

PR: https://git.openjdk.org/jdk17u-dev/pull/1823