pub trait CfgMatchesLintEmitter {
    // Required method
    fn emit_span_lint(
        &self,
        sess: &Session,
        lint: &'static Lint,
        sp: Span,
        diag: BuiltinLintDiag,
    );
}Expand description
Emitter of a builtin lint from cfg_matches.
Used to support emitting a lint (currently on check-cfg), either:
- as an early buffered lint (in 
rustc) - or has a “normal” lint from HIR (in 
rustdoc)