[clang] [llvm] [ARM][AArch64] BTI, GCS, PAC Module flag update. (PR #86212)

[Andrew Savonichev via llvm-commits]

https://github.com/asavonic commented:

LGTM overall. It is good that we address uncertainty of what these module flags actually mean. They went from "apply to all functions" to "only used to set an ELF flag", and it was impossible to tell which one it is.

https://github.com/llvm/llvm-project/pull/86212