Mark the feature as incomplete

Author: oli-obk

compiler/rustc_feature/src/unstable.rs

@@ -555,7 +555,7 @@ declare_features! (
     /// Allows using `#[optimize(X)]`.
     (unstable, optimize_attribute, "1.34.0", Some(54882)),
     /// Allows using pattern types.
-    (unstable, pattern_types, "CURRENT_RUSTC_VERSION", Some(54882)),
+    (internal, pattern_types, "CURRENT_RUSTC_VERSION", Some(54882)),
     /// Allows macro attributes on expressions, statements and non-inline modules.
     (unstable, proc_macro_hygiene, "1.30.0", Some(54727)),
     /// Allows `&raw const $place_expr` and `&raw mut $place_expr` expressions.