[llvm] [llvm][object] Expose `writeArchiveToStream` (PR #98254)

[David Blaikie via llvm-commits]

dwblaikie wrote:

This is documented here, btw: https://llvm.org/docs/CodeReview.html#code-review-workflow - if you did want to use a PR to run presubmits, there's a label you can apply that's just for documentation (in theory we could perhaps make the label suppress sending some notification emails, but haven't done that) so folks know your intent isn't to ask for precommit review/you believe this meets the bar (see documentation) for post-commit review.

https://github.com/llvm/llvm-project/pull/98254