{"ast_node_type":"function","tokens":[{"end":67,"kind":"keyword","start":0,"text":"fn"}]}
fn call_unreachable(cx: &ExtCtxt<'_>, span: Span) -> P<ast::Expr> {
/// Constructs an expression that calls the `unreachable` intrinsic.
    let span = cx.with_def_site_ctxt(span);