Remove all matching on ty.kind() outside cx

compiler/rustc_pattern_analysis/src/lints.rs

@@ -53,12 +53,11 @@ impl<'p, 'tcx> PatternColumn<'p, 'tcx> {
         }
         // If the type is opaque and it is revealed anywhere in the column, we take the revealed
         // version. Otherwise we could encounter constructors for the revealed type and crash.
-        let is_opaque = |ty: Ty<'tcx>| matches!(ty.kind(), ty::Alias(ty::Opaque, ..));
         let first_ty = self.patterns[0].ty();
-        if is_opaque(first_ty) {
+        if MatchCheckCtxt::is_opaque(first_ty) {
             for pat in &self.patterns {
                 let ty = pat.ty();
-                if !is_opaque(ty) {
+                if !MatchCheckCtxt::is_opaque(ty) {
                     return Some(ty);
                 }
             }