rustc: Move features from Session to GlobalCtxt

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

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -13,6 +13,7 @@ use rustc_ast::*;
 use rustc_ast::{walk_list, StaticItem};
 use rustc_ast_pretty::pprust::{self, State};
 use rustc_data_structures::fx::FxIndexMap;
+use rustc_feature::Features;
 use rustc_macros::Subdiagnostic;
 use rustc_parse::validate_attr;
 use rustc_session::lint::builtin::{
@@ -45,6 +46,7 @@ enum DisallowTildeConstContext<'a> {
 
 struct AstValidator<'a> {
     session: &'a Session,
+    features: &'a Features,
 
     /// The span of the `extern` in an `extern { ... }` block, if any.
     extern_mod: Option<&'a Item>,
@@ -1023,7 +1025,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                 }
                 self.check_type_no_bounds(bounds, "this context");
 
-                if self.session.features_untracked().lazy_type_alias {
+                if self.features.lazy_type_alias {
                     if let Err(err) = self.check_type_alias_where_clause_location(ty_alias) {
                         self.err_handler().emit_err(err);
                     }
@@ -1500,9 +1502,15 @@ fn deny_equality_constraints(
     this.err_handler().emit_err(err);
 }
 
-pub fn check_crate(session: &Session, krate: &Crate, lints: &mut LintBuffer) -> bool {
+pub fn check_crate(
+    session: &Session,
+    features: &Features,
+    krate: &Crate,
+    lints: &mut LintBuffer,
+) -> bool {
     let mut validator = AstValidator {
         session,
+        features,
         extern_mod: None,
         in_trait_impl: false,
         in_const_trait_impl: false,

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -514,10 +514,10 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
     }
 }
 
-pub fn check_crate(krate: &ast::Crate, sess: &Session) {
-    maybe_stage_features(sess, krate);
-    check_incompatible_features(sess);
-    let mut visitor = PostExpansionVisitor { sess, features: &sess.features_untracked() };
+pub fn check_crate(krate: &ast::Crate, sess: &Session, features: &Features) {
+    maybe_stage_features(sess, features, krate);
+    check_incompatible_features(sess, features);
+    let mut visitor = PostExpansionVisitor { sess, features };
 
     let spans = sess.parse_sess.gated_spans.spans.borrow();
     macro_rules! gate_all {
@@ -600,12 +600,12 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session) {
     visit::walk_crate(&mut visitor, krate);
 }
 
-fn maybe_stage_features(sess: &Session, krate: &ast::Crate) {
+fn maybe_stage_features(sess: &Session, features: &Features, krate: &ast::Crate) {
     // checks if `#![feature]` has been used to enable any lang feature
     // does not check the same for lib features unless there's at least one
     // declared lang feature
     if !sess.opts.unstable_features.is_nightly_build() {
-        let lang_features = &sess.features_untracked().declared_lang_features;
+        let lang_features = &features.declared_lang_features;
         if lang_features.len() == 0 {
             return;
         }
@@ -640,9 +640,7 @@ fn maybe_stage_features(sess: &Session, krate: &ast::Crate) {
     }
 }
 
-fn check_incompatible_features(sess: &Session) {
-    let features = sess.features_untracked();
-
+fn check_incompatible_features(sess: &Session, features: &Features) {
     let declared_features = features
         .declared_lang_features
         .iter()