Does anyone actually do that in a production code?

I myself am not native English speaker and use unicode when writing in my mother tongue, but in 20+ years of programming I've never seen anyone using non-ascii chars in their professionally written code? Of course, you use the language in localization files, and perhaps in comments occasionally - especially in TODO stuff that's not meant to be permanent - but not in the actual code, like e.g. for a variable or function names.

I'd actually consider it a bad idea, as it limits significantly who can manage that code in the future.