[llvm] [debug] Support 32-bit column number in DILocation (PR #201269)

[Stephen Tozer via llvm-commits]

SLTozer wrote:

Could you explain the purpose of this in a bit more detail? It's likely that a different solution will be needed, because there are some [upcoming plans](https://discourse.llvm.org/t/rfc-function-local-metadata-ir-and-api-changes/90966) to change the representation of DILocations, and a 32-bit column field won't be feasible under those changes; to be more exact, it could be done, but it would be fairly costly to do so, and so it would probably have to be enabled only behind a CMake flag, at which point it would probably be easier to just add a new field rather than using column as a side-channel.

https://github.com/llvm/llvm-project/pull/201269