"discriminator values can only be used with a c-like enum" wrong span

[mahkoh]

#[repr(u8)]
enum X {
    A = b'a',
    B(int),
}

fn main() {
}

test.rs:7:1: 7:3 error: discriminator values can only be used with a c-like enum
test.rs:7 fn main() {
          ^~