Fix simd_op_check_arm failure in LLVM trunk

[stevesuzuki-arm]

Fix the test failure which was found while verifying #9132 with the latest LLVM.

Checklist

• Tests added or updated (not required for docs, CI config, or typo fixes)

[stevesuzuki-arm]

simd_op_check_arm should fail with the halide_llvm at the time of creating this PR. But this will be necessary once we update LLVM to fix #9132

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
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Additional details and impacted files

@@           Coverage Diff           @@
##             main    #9140   +/-   ##
=======================================
  Coverage        ?   69.78%           
=======================================
  Files           ?      255           
  Lines           ?    77525           
  Branches        ?    18534           
=======================================
  Hits            ?    54103           
  Misses          ?    17967           
  Partials        ?     5455           

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[alexreinking]

@stevesuzuki-arm -- I'm going to merge these changes into #9141, which updates LLVM to the version that includes the necessary patches.

[alexreinking]

This has been folded into the LLVM upgrade PR.