nightly feature tracking: get rid of the per-feature bool fields

Author: RalfJung

clippy_lints/src/empty_enum.rs

@@ -64,7 +64,7 @@ impl LateLintPass<'_> for EmptyEnum {
     fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
         if let ItemKind::Enum(..) = item.kind
             // Only suggest the `never_type` if the feature is enabled
-            && cx.tcx.features().never_type
+            && cx.tcx.features().never_type()
             && let Some(adt) = cx.tcx.type_of(item.owner_id).instantiate_identity().ty_adt_def()
             && adt.variants().is_empty()
         {

clippy_lints/src/matches/match_same_arms.rs

@@ -114,7 +114,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'_>]) {
     let indexed_arms: Vec<(usize, &Arm<'_>)> = arms.iter().enumerate().collect();
     for (&(i, arm1), &(j, arm2)) in search_same(&indexed_arms, hash, eq) {
         if matches!(arm2.pat.kind, PatKind::Wild) {
-            if !cx.tcx.features().non_exhaustive_omitted_patterns_lint
+            if !cx.tcx.features().non_exhaustive_omitted_patterns_lint()
                 || is_lint_allowed(cx, NON_EXHAUSTIVE_OMITTED_PATTERNS, arm2.hir_id)
             {
                 let arm_span = adjusted_arm_span(cx, arm1.span);

clippy_lints/src/matches/redundant_guards.rs

@@ -251,7 +251,7 @@ fn emit_redundant_guards<'tcx>(
 fn expr_can_be_pat(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
     for_each_expr_without_closures(expr, |expr| {
         if match expr.kind {
-            ExprKind::ConstBlock(..) => cx.tcx.features().inline_const_pat,
+            ExprKind::ConstBlock(..) => cx.tcx.features().inline_const_pat(),
             ExprKind::Call(c, ..) if let ExprKind::Path(qpath) = c.kind => {
                 // Allow ctors
                 matches!(cx.qpath_res(&qpath, c.hir_id), Res::Def(DefKind::Ctor(..), ..))