[llvm] [AArch64][SME] Port all SME routines to RuntimeLibcalls (PR #152505)

[Benjamin Maxwell via llvm-commits]

MacDue wrote:

> What was this issue? Do you have an example?

It'd make `LibraryCalls_AlwaysAvailable` for each `SMEABI_LibCalls_PreserveMost_From_{X0,X1,X2}` collection of libcalls. Just removing the variables was simpler than worrying about the names. 

https://github.com/llvm/llvm-project/pull/152505