[llvm] [AArch64][v8.5A] Omit BTI for non-addr-taken static fns on Linux (PR #134669)

[Peter Smith via llvm-commits]

https://github.com/smithp35 commented:

I think this is the right thing to do as both GNU ld and lld will insert a BTI followed by a B when inserting a long branch thunk/veneer.

I've raised  an ABI issue to widen the sysvabi64 text to bare-metal targets too https://github.com/ARM-software/abi-aa/issues/321 as the gnu ld and lld changes would work there too.

I'm not sure what the state of BTI use is on Windows and Darwin. It would be safe to assume that any long-branch insertion didn't insert BTI instructions though.

https://github.com/llvm/llvm-project/pull/134669