rustc_type_ir: derive Debug for UnevaluatedConst

Author: GrigorenkoPV

compiler/rustc_type_ir/src/const_kind.rs

@@ -59,7 +59,7 @@ impl<I: Interner> fmt::Debug for ConstKind<I> {
 }
 
 /// An unevaluated (potentially generic) constant used in the type-system.
-#[derive_where(Clone, Copy, Hash, PartialEq, Eq; I: Interner)]
+#[derive_where(Clone, Copy, Debug, Hash, PartialEq, Eq; I: Interner)]
 #[derive(TypeVisitable_Generic, TypeFoldable_Generic, Lift_Generic)]
 #[cfg_attr(feature = "nightly", derive(TyDecodable, TyEncodable, HashStable_NoContext))]
 pub struct UnevaluatedConst<I: Interner> {
@@ -74,15 +74,6 @@ impl<I: Interner> UnevaluatedConst<I> {
     }
 }
 
-impl<I: Interner> fmt::Debug for UnevaluatedConst<I> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("UnevaluatedConst")
-            .field("def", &self.def)
-            .field("args", &self.args)
-            .finish()
-    }
-}
-
 rustc_index::newtype_index! {
     /// A **`const`** **v**ariable **ID**.
     #[encodable]