{"ast_node_type":"enum","tokens":[{"end":99,"kind":"keyword","start":0,"text":"//"}]}
                    // FIXME(fee1-dead) these could be variants of the UB info enum instead of this
                let Some(ty::VtblEntry::Method(fn_inst)) = vtable_entries.get(idx).copied() else {
                    throw_ub_custom!(fluent::const_eval_dyn_call_not_a_method);