{"ast_node_type":"variable","tokens":[{"end":61,"kind":"keyword","start":0,"text":"if"}]}
            if let VariantDiscr::Explicit(expr_did) = v.discr
            let mut discr = prev_discr.map_or(initial, |d| d.wrap_incr(tcx));
                && let Ok(new_discr) = self.eval_explicit_discr(tcx, expr_did)