[lld] [ELF] Enhance --no-allow-shlib-undefined to report non-exported definition (PR #70769)

[Peter Smith via llvm-commits]

https://github.com/smithp35 approved this pull request.

I agree. I think that this PR matches what I would expect from --no-allow-shlib-undefined.

https://github.com/llvm/llvm-project/pull/70769