RFR: 8352011: RISC-V: Two IR tests fail after JDK-8351662

[Fei Yang]

Hi, please review this small change fixing two IR tests.

These two tests which are enabled for riscv64 by JDK-8351662. But they fail on linux-riscv64 platforms where there is no support for RVV. They are expecting vector operations thus requires RVV support on this platform.

Testing: Same tests will be skipped on platforms without RVV after this change. Tagging @Hamlin-Li

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Commit messages:
 - 8352011: RISC-V: Two IR tests fail after JDK-8351662

Changes: https://git.openjdk.org/jdk/pull/24048/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24048&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8352011
  Stats: 4 lines in 2 files changed: 2 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/24048.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24048/head:pull/24048

PR: https://git.openjdk.org/jdk/pull/24048