[lld] [lld/COFF] Handle -start-lib / -end-lib better in /reproduce: output (PR #119752)

[Nico Weber via llvm-commits]

nico wrote:

> LGTM, this looks like a nice simplification! 

Thanks!
 
> With PDB outputs, I think the repro output has the problem that it will try to write the output into a directory that might not exist; this probably will need to be rewritten into something like just `/pdb:out.pdb` rather than the original PDB output path.

That sounds right.

> Then for really tricky things; if you have static libraries involved, that actually are thin libraries, i.e. just referencing other object files on disk, those aren't included in the repro package. And even if they would be, the static library would need to be rewritten to reference them with their relocatable name within the repro bundle.

lld/test/ELF/reproduce-thin-archive.s lld/test/MachO/reproduce-thin-archive-objc.s  lld/test/MachO/reproduce-thin-archives.s all exist, so someone seems to have thought about this in the past. We should probably do the same in the COFF port, if we aren't yet :)

https://github.com/llvm/llvm-project/pull/119752