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

[Daniil Kovalev via llvm-commits]

kovdan01 wrote:

@MaskRay I'm merging to resolve pauthtest buildbot failures appearing after prior merge of stacked #198327 https://lab.llvm.org/buildbot/#/builders/227

If any other concerns remain, I would be happy to address them in a follow-up PR.

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