[clang] [clang] assert fail when number of arguments in pack exceed implement… (PR #74220)

[Shafik Yaghmour via cfe-commits]

shafik wrote:

> Thanks for this PR! Emitting a diag in `TransformTemplateParmRefExpr` would probably a better way to go about it. It's not clear to me that the assert` is an improvement , and adding a diag would not be a lot more work. Would that be something you would be willing to explore?

Agreed.

https://github.com/llvm/llvm-project/pull/74220