[llvm] [dsymutil][DWARFLinker] Refactor handling mergeable libraries. (PR #80615)

[Alexey Lapshin via llvm-commits]

avl-llvm wrote:

> > I did not understand what should be done for the tests. Could you point for the relocation map reference which should be deleted, please?
> 
> All the `.dSYM` files under `test/tools/dsymutil/Inputs/`, with the `Contents/Resources/Relocations/` directory

Oh I see. Thanks. Removed Contents/Resources/Relocations.

https://github.com/llvm/llvm-project/pull/80615