[clang] [Clang][NFC] Consolidate the parameter check for the `requires` expression parameter. (PR #110773)

[Matheus Izvekov via cfe-commits]

mizvekov wrote:

> Thank you so much for your quick review! However, it seems the current CI is blocked by the issues mentioned in #110783 :(

I wouldn't be worried about that for a simple change like this, you can go ahead and merge.

https://github.com/llvm/llvm-project/pull/110773