[vectorIntrinsics+fp16] RFR: 8366432: Post-merge aarch64 build fixes

[Jatin Bhateja]

Follow-up patch for post-merger AArch64 build fixes
https://github.com/openjdk/panama-vector/pull/230#issuecomment-3236611372

Validated on Google AXION, all JTreg tests are passing on AArch64 as well.
 
Best regards,
Jatin

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Commit messages:
 - Post-merge aarch64 build fixes

Changes: https://git.openjdk.org/panama-vector/pull/232/files
  Webrev: https://webrevs.openjdk.org/?repo=panama-vector&pr=232&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8366432
  Stats: 44 lines in 3 files changed: 6 ins; 37 del; 1 mod
  Patch: https://git.openjdk.org/panama-vector/pull/232.diff
  Fetch: git fetch https://git.openjdk.org/panama-vector.git pull/232/head:pull/232

PR: https://git.openjdk.org/panama-vector/pull/232