[clang] [Clang][Sema]: Diagnose lambda to bool implicit casts (PR #83152)

[Shafik Yaghmour via cfe-commits]

https://github.com/shafik commented:

Thank you for this fix. I am happy the changes were not too different from my suggestion. Sometimes problems end up being more difficult then they seem initially.

https://github.com/llvm/llvm-project/pull/83152