[clang] [Clang] Diagnose function parameters used in lambda bodies in default arguments (PR #235057)

[Usef Ahmed via cfe-commits]

usefahmed07 wrote:

> Make sure you have detailed any AI usage before moving forward.
> 
> The fix itself looks like a workaround rather than a fix.

I've updated the PR description with AI usage details and tested all relevant cases. Everything works as expected. If you have a more fundamental solution in mind, please let me know so we can discuss and implement it.

https://github.com/llvm/llvm-project/pull/235057