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

[Abid Qadeer via llvm-commits]

abidh wrote:

> (might be worth checking where the earlier version of the check was (before fortran - looks like it just checked the upper bound was >= 0) - and if the author is still around, cc them on this in case they want to protest that checking that is really important or something)

I have removed the check that Subrange/GenericSubrange must contain count or upper bound. I have also removed `CurrentSourceLang` and updated the tests accordingly.

>From your comments, I guess that you also wanted to remove the `count >= -1` check. I have left it there for now. AsmParser catches the case if you give it a file with `count < -1`. I thought that similar check should stay on the Verifier too. The `count >= -1` check was added by @dexonsmith in 53855f05d315ccfbdc14d0ef2230b008a8e44adc.


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