[clang] [Clang][ItaniumMangle] Fix infinite recursion mangling a lambda in an enable_if condition (PR #234915)

[Eugene Velesevich via cfe-commits]

TabbySqui wrote:

> Hello, @usefahmed07, while I was viewing your #234686, I thought about how the similar problem for `requires` expr has been solved. I hope it's okay with you, I used your test and commit header for this pr and added co-author.

please let me now, if I did something wrong

https://github.com/llvm/llvm-project/pull/234915