Auto merge of #120924 - xFrednet:rfc-2383-stabilization-party, r=Urgau,blyxyas

Let's `#[expect]` some lints: Stabilize `lint_reasons` (RFC 2383)

Let's give this another try! The [previous stabilization attempt](https://github.com/rust-lang/rust/pull/99063) was stalled by some unresolved questions. These have been discussed in a [lang team](https://github.com/rust-lang/lang-team/issues/191) meeting. The last open question, regarding the semantics of the `#[expect]` attribute was decided on in https://github.com/rust-lang/rust/issues/115980

I've just updated the [stabilization report](https://github.com/rust-lang/rust/issues/54503#issuecomment-1179563964) with the discussed questions and decisions. Luckily, the decision is inline with the current implementation.

This hopefully covers everything. Let's hope that the CI will be green like the spring.

fixes #115980
fixes #54503

---

r? `@wesleywiser`

Tacking Issue: https://github.com/rust-lang/rust/issues/54503
Stabilization Report: https://github.com/rust-lang/rust/issues/54503#issuecomment-1179563964
Documentation Update: https://github.com/rust-lang/reference/pull/1237

<!--
For Clippy:

changelog: [`allow_attributes`]: Is now available on stable, since the `lint_reasons` feature was stabilized
changelog: [`allow_attributes_without_reason`]: Is now available on stable, since the `lint_reasons` feature was stabilized
-->

---

Roses are red,
Violets are blue,
Let's expect lints,
With reason clues

2 files changed, 0 insertions, 15 deletions

diff --git a/compiler/rustc_lint/src/expect.rs b/compiler/rustc_lint/src/expect.rs
index 40db765da53..04c2ebf189f 100644
--- a/compiler/rustc_lint/src/expect.rs
+++ b/compiler/rustc_lint/src/expect.rs
@@ -3,7 +3,6 @@ use rustc_middle::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::lint::builtin::UNFULFILLED_LINT_EXPECTATIONS;
 use rustc_session::lint::LintExpectationId;
-use rustc_span::symbol::sym;
 use rustc_span::Symbol;
 
 pub(crate) fn provide(providers: &mut Providers) {
@@ -11,10 +10,6 @@ pub(crate) fn provide(providers: &mut Providers) {
 }
 
 fn check_expectations(tcx: TyCtxt<'_>, tool_filter: Option<Symbol>) {
-    if !tcx.features().active(sym::lint_reasons) {
-        return;
-    }
-
     let lint_expectations = tcx.lint_expectations(());
     let fulfilled_expectations = tcx.dcx().steal_fulfilled_expectation_ids();
 
diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs
index 1317af50a4a..0df34c32e38 100644
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -37,7 +37,6 @@ use rustc_session::lint::{
     },
     Level, Lint, LintExpectationId, LintId,
 };
-use rustc_session::parse::feature_err;
 use rustc_session::Session;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{Span, DUMMY_SP};
@@ -788,15 +787,6 @@ 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.features.lint_reasons {
-                                    feature_err(
-                                        &self.sess,
-                                        sym::lint_reasons,
-                                        item.span,
-                                        "lint reasons are experimental",
-                                    )
-                                    .emit();
-                                }
                                 reason = Some(rationale);
                             } else {
                                 sess.dcx().emit_err(MalformedAttribute {