[llvm] [DebugInfo] Preserve line and column number when merging debug info. (PR #129960)

[Reid Kleckner via llvm-commits]

https://github.com/rnk commented:

Thanks for the docs!

This makes me wonder if we should look into some higher-level integration testing that tracks the number of call sites that lack source locations, since call site source locations are critical for so many applications.

https://github.com/llvm/llvm-project/pull/129960