[lld] [PAC][lld] Do not emit AUTH relocs against undef weak non-preemptible symbols (PR #194636)

[Jessica Clarke via llvm-commits]

jrtc27 wrote:

In future please avoid doing that. Normally it's possible to land MC support, then LLD support, then CodeGen support, in that order, such that the tree is never broken. It looks like your first patch conflated MC support (new relocation emitted by the new directive) and CodeGen support (changing the expansion of the pseudo to emit the new directive / relocation), and the latter is what caused issues due to depending on LLD support?

https://github.com/llvm/llvm-project/pull/194636