[clang] [Clang] Fix Sema::checkArgCount for 0-arg functions (PR #139638)

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

> Can somebody merge when it's appropriate? I don't have merge rights.

Yup, we can land for you once precommit CI goes green. Thank you for letting us know!

https://github.com/llvm/llvm-project/pull/139638