[clang] [llvm] [clang][llvm][aarch64] Add aarch64_sme_in_streaming_mode intrinsic (PR #120265)

[Sander de Smalen via llvm-commits]

https://github.com/sdesmalen-arm commented:

Could you add some rationale for adding the intrinsic to the commit message?

https://github.com/llvm/llvm-project/pull/120265