RFR: 8357695: RISC-V: Move vector intrinsic condition checks into match_rule_supported_vector [v2]

[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
> * [x]  Linux riscv64 server release build on SG2042

Dingli Zhang has updated the pull request incrementally with one additional commit since the last revision:

  Remove redundant UseRVV and use vlen as the condition

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Changes:
  - all: https://git.openjdk.org/jdk/pull/25438/files
  - new: https://git.openjdk.org/jdk/pull/25438/files/dba658b5..8256e0d7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25438&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25438&range=00-01

  Stats: 9 lines in 1 file changed: 0 ins; 0 del; 9 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