+use crate::ty;
+use crate::ty::codec::{self as ty_codec, TyDecoder, TyEncoder};
+use crate::ty::context::TyCtxt;
+use crate::util::common::{time, time_ext};
+
+use errors::Diagnostic;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::thin_vec::ThinVec;
+use rustc_data_structures::sync::{Lrc, Lock, HashMapExt, Once};
+use rustc_data_structures::indexed_vec::{IndexVec, Idx};