Rollup merge of #93658 - cchiw:issue-77443-fix, r=joshtriplett

Stabilize `#[cfg(panic = "...")]`

[Stabilization PR](https://rustc-dev-guide.rust-lang.org/stabilization_guide.html#stabilization-pr) for #77443

compiler/rustc_feature/src/accepted.rs

@@ -70,6 +70,8 @@ declare_features! (
     (accepted, cfg_attr_multi, "1.33.0", Some(54881), None),
     /// Allows the use of `#[cfg(doctest)]`, set when rustdoc is collecting doctests.
     (accepted, cfg_doctest, "1.40.0", Some(62210), None),
+    /// Enables `#[cfg(panic = "...")]` config key.
+    (accepted, cfg_panic, "1.60.0", Some(77443), None),
     /// Allows `cfg(target_feature = "...")`.
     (accepted, cfg_target_feature, "1.27.0", Some(29717), None),
     /// Allows `cfg(target_vendor = "...")`.

compiler/rustc_feature/src/active.rs

@@ -306,8 +306,6 @@ declare_features! (
     (active, c_variadic, "1.34.0", Some(44930), None),
     /// Allows capturing disjoint fields in a closure/generator (RFC 2229).
     (incomplete, capture_disjoint_fields, "1.49.0", Some(53488), None),
-    /// Enables `#[cfg(panic = "...")]` config key.
-    (active, cfg_panic, "1.49.0", Some(77443), None),
     /// Allows the use of `#[cfg(sanitize = "option")]`; set when -Zsanitizer is used.
     (active, cfg_sanitize, "1.41.0", Some(39699), None),
     /// Allows `cfg(target_abi = "...")`.

compiler/rustc_feature/src/builtin_attrs.rs

@@ -34,7 +34,6 @@ const GATED_CFGS: &[GatedCfg] = &[
     (sym::target_has_atomic_load_store, sym::cfg_target_has_atomic, cfg_fn!(cfg_target_has_atomic)),
     (sym::sanitize, sym::cfg_sanitize, cfg_fn!(cfg_sanitize)),
     (sym::version, sym::cfg_version, cfg_fn!(cfg_version)),
-    (sym::panic, sym::cfg_panic, cfg_fn!(cfg_panic)),
 ];
 
 /// Find a gated cfg determined by the `pred`icate which is given the cfg's name.