Function rustc_typeck::check::check::format_discriminant_overflow

fn format_discriminant_overflow<'tcx>(
    tcx: TyCtxt<'tcx>,
    variant: &Variant<'_>,
    dis: Discr<'tcx>
) -> String

In the case that a discriminant is both a duplicate and an overflowing literal, we insert both the assigned discriminant and the literal it overflowed from into the formatted output. Otherwise we format the discriminant normally.