[clang] [llvm] [CodeGen][AArch64][FMV] PAC the stub_helper's frame on arm64e (PR #84704)

[Anton Korobeynikov via cfe-commits]

asl wrote:

Tagging @kovdan01 

Can the triple checks be generalized to checking about pauth-enabled subtarget feature? This way everything would work for ELF platforms eventually.

https://github.com/llvm/llvm-project/pull/84704