[llvm] [AArch64] Disable FastISel/GlobalISel for ZT0 state (PR #82768)

[Sander de Smalen via llvm-commits]

sdesmalen-arm wrote:

> Is the acle_sme_zero.c failing test unrelated? This looks sensible otherwise.

Thanks. Yes that failing test was unrelated. I've rebased the patch so that pre-commit will turn green.

https://github.com/llvm/llvm-project/pull/82768