Noreturn functions

[NTSFka]

How to declare functions which never returns. Those functions are useful when function is acts as termination so it exits whole application or always throws something.

• In C++ is [[noreturn]] attribute.
• In Swift is Never return type.
• In Rust is ! return type.

I don't think this is important now, but for the future version of the language. Mainly it helps the compiler to optimize code.