[lld] [llvm] [DTLTO][LLD][ELF] Support bitcode members of thin archives (PR #149425)

[Tobias Hieta via llvm-commits]

tru wrote:

Feels fairly safe - but it depends on when it lands. I wouldn't want to merge it right before final or post final.

https://github.com/llvm/llvm-project/pull/149425