[llvm] Fix merging of debug_str_offsets with multiple contributions (PR #90461)

[David Blaikie via llvm-commits]

dwblaikie wrote:

Thanks!

Generally I think we're moving away from checked in binary object files - could you make the test from checked in assembly instead (perhaps using @MaskRay's new https://llvm.org/docs/TestingGuide.html#elaborated-tests perhaps)

So if I'm understanding correctly - you're saying llvm-dwp did not work when an input was a DWP and was DWARFv5? huh, surprising oversight... oh, I guess not that many people use dwp files as input to dwp actions, so I can see how some people would've been working along fine with this state of affairs.

https://github.com/llvm/llvm-project/pull/90461