apply suggestion

Author: dingxiangfei2009

Diff for: compiler/rustc_feature/src/unstable.rs

@@ -425,8 +425,6 @@ declare_features! (
     (unstable, deprecated_suggestion, "1.61.0", Some(94785)),
     /// Allows deref patterns.
     (incomplete, deref_patterns, "1.79.0", Some(87121)),
-    /// Allows deriving traits as per `CoercePointee` specification
-    (unstable, derive_coerce_pointee, "1.79.0", Some(123430)),
     /// Controls errors in trait implementations.
     (unstable, do_not_recommend, "1.67.0", Some(51992)),
     /// Tells rustdoc to automatically generate `#[doc(cfg(...))]`.