[clang] [llvm] [AArch64][SME] Remove immediate argument restriction for svldr and svstr (PR #68565)

[Eli Friedman via cfe-commits]

https://github.com/efriedma-quic commented:

The resulting code here still isn't great quality for the case where the constant isn't folded.  Maybe worth considering doing the lowering earlier (DAGCombine?  Maybe even a late IR optimization?), so the lowered arithmetic can be optimized.

https://github.com/llvm/llvm-project/pull/68565