[clang] Use cmake to find perl executable (PR #91275)

[Artem Dergachev via cfe-commits]

https://github.com/haoNoQ approved this pull request.

Looks great thanks a lot!!

I can confirm that it works for me on a mac too.

@jroelofs's comment is on point.

https://github.com/llvm/llvm-project/pull/91275