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

[Jon Roelofs via cfe-commits]

jroelofs wrote:

some tests need UTC-ing because of the new attrs on the resolver:
```
  Clang :: CodeGen/attr-cpuspecific.c
  Clang :: CodeGen/attr-target-clones.c
  Clang :: CodeGen/attr-target-mv-va-args.c
  Clang :: CodeGen/attr-target-mv.c
  Clang :: CodeGen/attr-target-version.c
  Clang :: CodeGenCXX/attr-cpuspecific.cpp
  Clang :: CodeGenCXX/attr-target-clones.cpp
  Clang :: CodeGenCXX/attr-target-mv-diff-ns.cpp
  Clang :: CodeGenCXX/attr-target-mv-member-funcs.cpp
  Clang :: CodeGenCXX/attr-target-mv-out-of-line-defs.cpp
  Clang :: CodeGenCXX/attr-target-mv-overloads.cpp
 ```

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