RFR: 8351348: x86_64: remove redundant supports_float16 check

[Hamlin Li]

Hi,
Can you help to review this simple patch?
`supports_float16()` is invoked in `is_intrinsic_available -> is_intrinsic_supported`, so there is no need to call it explicitly.

Thanks

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Commit messages:
 - initial commit

Changes: https://git.openjdk.org/jdk/pull/23932/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23932&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8351348
  Stats: 8 lines in 1 file changed: 0 ins; 2 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/23932.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23932/head:pull/23932

PR: https://git.openjdk.org/jdk/pull/23932