[clang] [AArch64][SME] Warn when using a streaming builtin from a non-streaming function (PR #75487)

[Sam Tebbs via cfe-commits]

SamTebbs33 wrote:

@nico I tried to cherry-pick your commit (c60663d128f8e0dccd418bdf16ecc403b96aa74a)  into my branch but for some reason it was always empty. It might be best for you to try recommitting it now.

https://github.com/llvm/llvm-project/pull/75487