[llvm] [RemoveDIs][DebugInfo] Update SROA to handle DPVAssigns (PR #78475)

[Orlando Cazalet-Hyams via llvm-commits]

https://github.com/OCHyams approved this pull request.

Code changes all LGTM, but this needs tests too. What's your intended strategy for landing code/test changes?

FWIW For DPDeclares I updated the tests for each pass in the same patch the code was update (e.g., you would update SROA tests here), with the tests "rotten green" (not actually testing the DPDeclares) until the capstone patch that enabled dbg.declare -> DPDeclare landed.

https://github.com/llvm/llvm-project/pull/78475