RFR: 8356642: RISC-V: enable hotspot/jtreg/compiler/vectorapi/VectorFusedMultiplyAddSubTest.java

[Hamlin Li]

Hi,
Can you help to review this patch?

API comibnation like `av.lanewise(VectorOperators.FMA, bv.neg(), cv, mask).intoArray(fr, i);` should be able to be optimized to some special instruct rather than a bunch of instructs.

We can not verify IR node (via `beforeMatchingNameRegex`) in PrintIdeal phase, as it does not mean that the special instruct are generated in FINAL CODE phase, it could be a combination of multiple different instruct.

As riscv use different instruct names, so I create new ones in IRNode.java. 

Thanks

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Commit messages:
 - modify summary
 - initial commit

Changes: https://git.openjdk.org/jdk/pull/25145/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25145&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8356642
  Stats: 57 lines in 2 files changed: 34 ins; 0 del; 23 mod
  Patch: https://git.openjdk.org/jdk/pull/25145.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25145/head:pull/25145

PR: https://git.openjdk.org/jdk/pull/25145