[llvm] [DataFlowSanitizer] Properly add ext attributes on arguments as needed. (PR #225443)

[Jonas Paulsson via llvm-commits]

JonPsson1 wrote:

To be honest, this time I have tried to use IBM Bob and some of these parts have been originally suggested by it. They make sense to me while looking at the specific test problems being resolved, but I agree that there may well be a better solution to this at some point as this is not really clear to me how all these declarations are handled. The changes I have inserted fix the problems I have seen and seem harmeless under the assumption that they only affect the instrumented calls and all integer arguments added are all unsigned.

https://github.com/llvm/llvm-project/pull/225443