OverflowOp,
StaticBuilderMethods,
};
-use rustc_data_structures::stable_set::FxHashSet;
+use rustc_data_structures::fx::FxHashSet;
use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
use rustc_middle::ty::layout::{FnAbiError, FnAbiOfHelpers, FnAbiRequest, HasParamEnv, HasTyCtxt, LayoutError, LayoutOfHelpers, TyAndLayout};
use rustc_span::Span;