use rustc_attr::{self as attr, ConstStability, Stability};
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_errors::struct_span_err;
use rustc_attr::{self as attr, ConstStability, Stability};
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_errors::struct_span_err;