[clang] [llvm] [Clang] Fix argument extensions in CGBlocks.cpp (PR #111740)

[Jonas Paulsson via cfe-commits]

JonPsson1 wrote:

> I looked to see how hard it would be to lower the clang type... seems like it's not hard. Pushed #113506. Let me know what you think.
> 
> If there's some complication I'm not seeing, I think your suggested API in the current version of this patch makes sense... but using clang types seems much easier on the caller side.

I think that seems to work well, thanks.

https://github.com/llvm/llvm-project/pull/111740