RFR: 8368206: RISC-V: compiler/vectorapi/VectorMaskCompareNotTest.java fails when running without RVV

[Dingli Zhang]

Hi,
Can you help to review this patch? Thanks!

We noticed that compiler/vectorapi/VectorMaskCompareNotTest.java fails when running on sg2042.
On RISC-V without RVV, ofLargestShape(long.class) falls back to 64 bits (see getMaxVectorBitSize in VectorShape.java),
leading to VectorShape.forBitSize(32) which is unsupported and throws IllegalArgumentException.

### Test (fastdebug)
- [x] Run compiler/vectorapi/VectorMaskCompareNotTest.java on sg2042

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Commit messages:
 - 8368206: RISC-V: compiler/vectorapi/VectorMaskCompareNotTest.java fails when running without RVV

Changes: https://git.openjdk.org/jdk/pull/27414/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27414&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8368206
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/27414.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27414/head:pull/27414

PR: https://git.openjdk.org/jdk/pull/27414