use crate::ty::subst::{GenericArg, SubstsRef};
use crate::ty::util::AlwaysRequiresDrop;
use crate::ty::GeneratorDiagnosticData;
-use crate::ty::{self, CrateInherentImpls, ParamEnvAnd, Ty, TyCtxt};
+use crate::ty::{self, CrateInherentImpls, ParamEnvAnd, Ty, TyCtxt, UnusedGenericParams};
use rustc_ast as ast;
use rustc_ast::expand::allocator::AllocatorKind;
use rustc_attr as attr;
use rustc_hir::hir_id::OwnerId;
use rustc_hir::lang_items::{LangItem, LanguageItems};
use rustc_hir::{Crate, ItemLocalId, TraitCandidate};
-use rustc_index::{bit_set::FiniteBitSet, vec::IndexVec};
+use rustc_index::vec::IndexVec;
use rustc_session::config::{EntryFnType, OptLevel, OutputFilenames, SymbolManglingVersion};
use rustc_session::cstore::{CrateDepKind, CrateSource};
use rustc_session::cstore::{ExternCrate, ForeignModule, LinkagePreference, NativeLib};