[llvm] Add DISubrangeType (PR #126772)

[Paul T Robinson via llvm-commits]

pogo59 wrote:

FTR, Pascal also has subrange types, so this can be useful beyond Ada. I suspect Pascal compilers would also use a bias if the type is used as an array index, and maybe if it was a packed type, although I haven't worked on any Pascal compilers for decades.

https://github.com/llvm/llvm-project/pull/126772