RFR: 8357695: RISC-V: Move vector intrinsic condition checks into match_rule_supported_vector

[Dingli Zhang]

Hi all,
Please take a look and review this PR, thanks!

Currently, the match_rule_supported function in riscv.ad contains checks for vector-related intrinsics (e.g., FmaVF, FmaVD, RoundVF, RoundVD). These checks can be centralized into the match_rule_supported_vector function in the riscv_v.ad file, ensuring consistent handling in their appropriate context.

### Testing
* [ ]  Linux riscv64 server release build on SG2042

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Commit messages:
 - 8357695: RISC-V: Move vector intrinsic condition checks into match_rule_supported_vector

Changes: https://git.openjdk.org/jdk/pull/25438/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25438&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8357695
  Stats: 31 lines in 2 files changed: 16 ins; 15 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/25438.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25438/head:pull/25438

PR: https://git.openjdk.org/jdk/pull/25438