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

[Abid Qadeer via llvm-commits]

abidh wrote:

> In principle this LGTM, perhaps other reviewers could chime in though. In an ideal world we'd have a test that ensures this behaviour continues to be present, is there an LLVM-IR input from flang that triggers the previous error, and that we can have in the LLVM DebugInfo test suite?

I have added a test.

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