[lang design] [discuss] is introducing never type a good idea?

[shamiao]

never type is currently implemented by returning a generic value which is impossible to initialize, which is a really nice workaround:

pub fn abort[T](msg : String) -> T = "%abort"

I wonder if the formal never type is worth introduced to the language? May be used on 2 minor parts:

A) dead code removal

B) ignore non-exist arms of enums:

let input: Result[Int, Never] = Ok(1)
match input {
    Ok(_v1) => { ... }
    // `Err` arm is not needed
}
let Ok(_v2) = input  // ... even match block is not needed, values can be extracted by matching the only pattern `Ok(_)`

If the never type is decided to not introduce, it's still recommended to reserve never and Never as keywords.