remove unnecessary TypeFoldable impls

compiler/rustc_middle/src/ty/mod.rs

@@ -1031,6 +1031,8 @@ pub struct ParamEnvAnd<'tcx, T> {
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable)]
 #[derive(TypeVisitable, TypeFoldable)]
 pub struct TypingEnv<'tcx> {
+    #[type_foldable(identity)]
+    #[type_visitable(ignore)]
     pub typing_mode: TypingMode<'tcx>,
     pub param_env: ParamEnv<'tcx>,
 }

compiler/rustc_type_ir/src/canonical.rs

@@ -199,7 +199,6 @@ impl<I: Interner> CanonicalVarKind<I> {
 /// usize or f32). In order to faithfully reproduce a type, we need to
 /// know what set of types a given type variable can be unified with.
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
-#[derive(TypeVisitable_Generic, TypeFoldable_Generic)]
 #[cfg_attr(
     feature = "nightly",
     derive(Decodable_NoContext, Encodable_NoContext, HashStable_NoContext)

compiler/rustc_type_ir/src/const_kind.rs

@@ -92,15 +92,10 @@ rustc_index::newtype_index! {
 
 /// An inference variable for a const, for use in const generics.
 #[derive(Copy, Clone, Eq, PartialEq, PartialOrd, Ord, Hash)]
-#[derive(TypeVisitable_Generic, TypeFoldable_Generic)]
 #[cfg_attr(feature = "nightly", derive(Encodable_NoContext, Decodable_NoContext))]
 pub enum InferConst {
     /// Infer the value of the const.
-    Var(
-        #[type_foldable(identity)]
-        #[type_visitable(ignore)]
-        ConstVid,
-    ),
+    Var(ConstVid),
     /// A fresh const variable. See `infer::freshen` for more details.
     Fresh(u32),
 }

compiler/rustc_type_ir/src/infer_ctxt.rs

@@ -1,7 +1,6 @@
 use derive_where::derive_where;
 #[cfg(feature = "nightly")]
 use rustc_macros::{Decodable_NoContext, Encodable_NoContext, HashStable_NoContext};
-use rustc_type_ir_macros::{TypeFoldable_Generic, TypeVisitable_Generic};
 
 use crate::fold::TypeFoldable;
 use crate::inherent::*;
@@ -20,7 +19,6 @@ use crate::{self as ty, Interner};
 /// If neither of these functions are available, feel free to reach out to
 /// t-types for help.
 #[derive_where(Clone, Copy, Hash, PartialEq, Eq, Debug; I: Interner)]
-#[derive(TypeVisitable_Generic, TypeFoldable_Generic)]
 #[cfg_attr(
     feature = "nightly",
     derive(Encodable_NoContext, Decodable_NoContext, HashStable_NoContext)