Function pgrx_pg_sys::cost_merge_append

pub unsafe fn cost_merge_append(
    arg_path: *mut Path,
    arg_root: *mut PlannerInfo,
    arg_pathkeys: *mut List,
    arg_n_streams: c_int,
    arg_input_startup_cost: Cost,
    arg_input_total_cost: Cost,
    arg_tuples: f64
)