{"ast_node_type":"other","tokens":[{"end":68,"kind":"keyword","start":0,"text":"if"}]}
                if matches!(const_val, mir::ConstValue::ZeroSized) {
                let const_val = cx.valtree_to_const_val(cv);
                    crate::ty::TyConstKind::ZSTValue(cv.ty.stable(tables, cx))