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 {
 fncheck_item(&mutself,cx:&LateContext<'_>,item:&Item<'_>){
 ifletItemKind::Enum(..) = item.kind
 // Only suggest the `never_type` if the feature is enabled
- && cx.tcx.features().never_type
+ && cx.tcx.features().never_type()
  && letSome(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))insearch_same(&indexed_arms, hash, eq){
 ifmatches!(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>(
 fnexpr_can_be_pat(cx:&LateContext<'_>,expr:&Expr<'_>) -> bool{
 for_each_expr_without_closures(expr, |expr| {
 ifmatch expr.kind{
-ExprKind::ConstBlock(..) => cx.tcx.features().inline_const_pat,
+ExprKind::ConstBlock(..) => cx.tcx.features().inline_const_pat(),
 ExprKind::Call(c, ..)ifletExprKind::Path(qpath) = c.kind => {
 // Allow ctors
 matches!(cx.qpath_res(&qpath, c.hir_id),Res::Def(DefKind::Ctor(..), ..))