clippy: update is_stable_const_fn helper for multiple const-stability attrs

Author: dianne

src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs

@@ -380,7 +380,7 @@ fn check_terminator<'tcx>(
 fn is_stable_const_fn(tcx: TyCtxt<'_>, def_id: DefId, msrv: &Msrv) -> bool {
     tcx.is_const_fn(def_id)
         && tcx.lookup_const_stability(def_id).is_none_or(|const_stab| {
-            if let rustc_attr::StabilityLevel::Stable { since, .. } = const_stab.level {
+            if let rustc_attr::ConstStabilityLevel::Stable { since, .. } = const_stab.level {
                 // Checking MSRV is manually necessary because `rustc` has no such concept. This entire
                 // function could be removed if `rustc` provided a MSRV-aware version of `is_stable_const_fn`.
                 // as a part of an unimplemented MSRV check https://github.com/rust-lang/rust/issues/65262.
@@ -393,11 +393,11 @@ fn is_stable_const_fn(tcx: TyCtxt<'_>, def_id: DefId, msrv: &Msrv) -> bool {
 
                 msrv.meets(const_stab_rust_version)
             } else {
-                // Unstable const fn, check if the feature is enabled. We need both the regular stability
-                // feature and (if set) the const stability feature to const-call this function.
+                // Unstable const fn, check if the features are enabled. We need both the regular stability
+                // features and (if set) the const stability features to const-call this function.
                 let stab = tcx.lookup_stability(def_id);
-                let is_enabled = stab.is_some_and(|s| s.is_stable() || tcx.features().enabled(s.feature))
-                    && const_stab.feature.is_none_or(|f| tcx.features().enabled(f));
+                let is_enabled = stab.is_some_and(|s| tcx.features().all_enabled(s.unstable_features()))
+                    && tcx.features().all_enabled(const_stab.unstable_features());
                 is_enabled && msrv.current().is_none()
             }
         })