[llvm] [AArch64] Fix frame-pointer offset with hazard padding (PR #118091)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

(Following is not intended to block this patch.)

Why are we generating code like this in the first place?  It looks really silly when you subtract 1056 from sp, then split the frame stores because the offsets are too large, then subtract another 1024 from sp.  Better to just generate `x29, x30, [sp, #-32]!`, then subtract 2048.

https://github.com/llvm/llvm-project/pull/118091