[riscv-port-jdk17u:riscv-port] RFR: 8287970: riscv: jdk/incubator/vector/*VectorTests failing

[Gui Cao]

Please review this backport to riscv-port-jdk17u.
Backport of [JDK-8287970](https://bugs.openjdk.org/browse/JDK-8287970). Applies cleanly. 

Note that the vector operation VectorOperations.BIT_COUNT has not been introduced in this version, so even if the node Op_PopCountVI exists, it will not cause the test case to fail. Also, the node Op_PopCountVL has not been introduced in this version, so there is no need to add this node to the list of unsupported vectors

Testing:
- test/jdk/jdk/incubator/vector (release/fastdebug on qemu with UseRVV)
- Tier1 passed without new failure on unmacthed (release).

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Commit messages:
 - backport 8287970: riscv: jdk/incubator/vector/*VectorTests failing

Changes: https://git.openjdk.org/riscv-port-jdk17u/pull/11/files
 Webrev: https://webrevs.openjdk.org/?repo=riscv-port-jdk17u&pr=11&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8287970
  Stats: 13 lines in 1 file changed: 1 ins; 12 del; 0 mod
  Patch: https://git.openjdk.org/riscv-port-jdk17u/pull/11.diff
  Fetch: git fetch https://git.openjdk.org/riscv-port-jdk17u pull/11/head:pull/11

PR: https://git.openjdk.org/riscv-port-jdk17u/pull/11