RFR: 8343060: RISC-V: enable TestFloat16VectorConvChain for riscv

[Hamlin Li]

Hi,
Can you help to review this simple patch?
Both JDK-8336827 and JDK-8335860 modified the test in the wrong way for riscv, need to fix it for riscv.
Thanks!

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Commit messages:
 - initial commit
 - Merge branch 'openjdk:master' into master
 - Merge branch 'openjdk:master' into master
 - Revert "initial commit"
 - initial commit

Changes: https://git.openjdk.org/jdk/pull/21709/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21709&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8343060
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/21709.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21709/head:pull/21709

PR: https://git.openjdk.org/jdk/pull/21709