[llvm] [DebugInfo] Swap 'Unit' and 'Type' positions in DISubprogram. (PR #96474)

[Abid Qadeer via llvm-commits]

abidh wrote:

> This change will need test coverage - it might be worth keeping the existing tests around and turning them into code generation tests, to check we can generate DWARF even when we violate these verifier checks? And we'll need a new test for the intended functionality that motivated you to look into this issue in the first place? (the missing language code/incorrect bounds checking issue? Though I realize it's sort of a non-issue once there's no bounds checking at all anyway... )

I have added a test that checks that debug info is generated correctly when these conditions are violated. The test covers the original motivating case that compilation does not fail for things like `!DISubrange()`.

https://github.com/llvm/llvm-project/pull/96474