Remove AlwaysLiveLocals wrapper struct

It is just a wrapper around a `BitSet` and
doesn't have any functionality of its own.

compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -15,7 +15,7 @@ use rustc_middle::ty::layout::{
 use rustc_middle::ty::{
     self, query::TyCtxtAt, subst::SubstsRef, ParamEnv, Ty, TyCtxt, TypeFoldable,
 };
-use rustc_mir_dataflow::storage::AlwaysLiveLocals;
+use rustc_mir_dataflow::storage::always_live_locals;
 use rustc_query_system::ich::StableHashingContext;
 use rustc_session::Limit;
 use rustc_span::{Pos, Span};
@@ -715,7 +715,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
         // Now mark those locals as dead that we do not want to initialize
         // Mark locals that use `Storage*` annotations as dead on function entry.
-        let always_live = AlwaysLiveLocals::new(self.body());
+        let always_live = always_live_locals(self.body());
         for local in locals.indices() {
             if !always_live.contains(local) {
                 locals[local].value = LocalValue::Dead;