rustc: Move features from Session to GlobalCtxt

Removes two pieces of mutable state.
Follow up to #114622.

compiler/rustc_lint/src/levels.rs

@@ -12,6 +12,7 @@ use rustc_ast as ast;
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{DecorateLint, DiagnosticBuilder, DiagnosticMessage, MultiSpan};
+use rustc_feature::Features;
 use rustc_hir as hir;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::HirId;
@@ -119,6 +120,7 @@ fn lint_expectations(tcx: TyCtxt<'_>, (): ()) -> Vec<(LintExpectationId, LintExp
 
     let mut builder = LintLevelsBuilder {
         sess: tcx.sess,
+        features: tcx.features(),
         provider: QueryMapExpectationsWrapper {
             tcx,
             cur: hir::CRATE_HIR_ID,
@@ -148,6 +150,7 @@ fn shallow_lint_levels_on(tcx: TyCtxt<'_>, owner: hir::OwnerId) -> ShallowLintLe
 
     let mut levels = LintLevelsBuilder {
         sess: tcx.sess,
+        features: tcx.features(),
         provider: LintLevelQueryMap {
             tcx,
             cur: owner.into(),
@@ -435,6 +438,7 @@ impl<'tcx> Visitor<'tcx> for LintLevelsBuilder<'_, QueryMapExpectationsWrapper<'
 
 pub struct LintLevelsBuilder<'s, P> {
     sess: &'s Session,
+    features: &'s Features,
     provider: P,
     warn_about_weird_lints: bool,
     store: &'s LintStore,
@@ -448,12 +452,14 @@ pub(crate) struct BuilderPush {
 impl<'s> LintLevelsBuilder<'s, TopDown> {
     pub(crate) fn new(
         sess: &'s Session,
+        features: &'s Features,
         warn_about_weird_lints: bool,
         store: &'s LintStore,
         registered_tools: &'s RegisteredTools,
     ) -> Self {
         let mut builder = LintLevelsBuilder {
             sess,
+            features,
             provider: TopDown { sets: LintLevelSets::new(), cur: COMMAND_LINE },
             warn_about_weird_lints,
             store,
@@ -526,6 +532,10 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
         self.sess
     }
 
+    pub(crate) fn features(&self) -> &Features {
+        self.features
+    }
+
     pub(crate) fn lint_store(&self) -> &LintStore {
         self.store
     }
@@ -716,7 +726,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                     ast::MetaItemKind::NameValue(ref name_value) => {
                         if item.path == sym::reason {
                             if let ast::LitKind::Str(rationale, _) = name_value.kind {
-                                if !self.sess.features_untracked().lint_reasons {
+                                if !self.features.lint_reasons {
                                     feature_err(
                                         &self.sess.parse_sess,
                                         sym::lint_reasons,
@@ -992,7 +1002,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
     #[track_caller]
     fn check_gated_lint(&self, lint_id: LintId, span: Span) -> bool {
         if let Some(feature) = lint_id.lint.feature_gate {
-            if !self.sess.features_untracked().enabled(feature) {
+            if !self.features.enabled(feature) {
                 let lint = builtin::UNKNOWN_LINTS;
                 let (level, src) = self.lint_level(builtin::UNKNOWN_LINTS);
                 struct_lint_level(