Auto merge of #137164 - matthiaskrgr:rollup-dj5826k, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #137095 (Replace some u64 hashes with Hash64)
 - #137100 (HIR analysis: Remove unnecessary abstraction over list of clauses)
 - #137105 (Restrict DerefPure for Cow<T> impl to T = impl Clone, [impl Clone], str.)
 - #137120 (Enable `relative-path-include-bytes-132203` rustdoc-ui test on Windows)
 - #137125 (Re-add missing empty lines in the releases notes)
 - #137145 (use add-core-stubs / minicore for a few more tests)
 - #137149 (Remove SSE ABI from i586-pc-windows-msvc)

r? `@ghost`
`@rustbot` modify labels: rollup

53 files changed, 238 insertions, 279 deletions

diff --git a/compiler/rustc_abi/Cargo.toml b/compiler/rustc_abi/Cargo.toml
index 1013f1d3958..3d6f4a6a109 100644
--- a/compiler/rustc_abi/Cargo.toml
+++ b/compiler/rustc_abi/Cargo.toml
@@ -9,6 +9,7 @@ bitflags = "2.4.1"
 rand = { version = "0.8.4", default-features = false, optional = true }
 rand_xoshiro = { version = "0.6.0", optional = true }
 rustc_data_structures = { path = "../rustc_data_structures", optional = true  }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_index = { path = "../rustc_index", default-features = false }
 rustc_macros = { path = "../rustc_macros", optional = true }
 rustc_serialize = { path = "../rustc_serialize", optional = true  }
diff --git a/compiler/rustc_abi/src/layout.rs b/compiler/rustc_abi/src/layout.rs
index b8773f9ff38..45cd0b517f6 100644
--- a/compiler/rustc_abi/src/layout.rs
+++ b/compiler/rustc_abi/src/layout.rs
@@ -2,6 +2,7 @@ use std::fmt::{self, Write};
 use std::ops::{Bound, Deref};
 use std::{cmp, iter};
 
+use rustc_hashes::Hash64;
 use rustc_index::Idx;
 use tracing::debug;
 
@@ -133,7 +134,7 @@ impl<Cx: HasDataLayout> LayoutCalculator<Cx> {
             size,
             max_repr_align: None,
             unadjusted_abi_align: align.abi,
-            randomization_seed: combined_seed,
+            randomization_seed: Hash64::new(combined_seed),
         }
     }
 
@@ -226,7 +227,7 @@ impl<Cx: HasDataLayout> LayoutCalculator<Cx> {
             size: Size::ZERO,
             max_repr_align: None,
             unadjusted_abi_align: dl.i8_align.abi,
-            randomization_seed: 0,
+            randomization_seed: Hash64::ZERO,
         }
     }
 
@@ -1058,7 +1059,7 @@ impl<Cx: HasDataLayout> LayoutCalculator<Cx> {
         // unsizable tail fields are excluded so that we use the same seed for the sized and unsized layouts.
         let field_seed = fields_excluding_tail
             .iter()
-            .fold(0u64, |acc, f| acc.wrapping_add(f.randomization_seed));
+            .fold(Hash64::ZERO, |acc, f| acc.wrapping_add(f.randomization_seed));
 
         if optimize_field_order && fields.len() > 1 {
             // If `-Z randomize-layout` was enabled for the type definition we can shuffle
@@ -1072,7 +1073,7 @@ impl<Cx: HasDataLayout> LayoutCalculator<Cx> {
                     // `ReprOptions.field_shuffle_seed` is a deterministic seed we can use to randomize field
                     // ordering.
                     let mut rng = rand_xoshiro::Xoshiro128StarStar::seed_from_u64(
-                        field_seed.wrapping_add(repr.field_shuffle_seed),
+                        field_seed.wrapping_add(repr.field_shuffle_seed).as_u64(),
                     );
 
                     // Shuffle the ordering of the fields.
diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs
index da1c706d67c..dbb4bed5cdd 100644
--- a/compiler/rustc_abi/src/lib.rs
+++ b/compiler/rustc_abi/src/lib.rs
@@ -50,6 +50,7 @@ use std::str::FromStr;
 use bitflags::bitflags;
 #[cfg(feature = "nightly")]
 use rustc_data_structures::stable_hasher::StableOrd;
+use rustc_hashes::Hash64;
 use rustc_index::{Idx, IndexSlice, IndexVec};
 #[cfg(feature = "nightly")]
 use rustc_macros::{Decodable_Generic, Encodable_Generic, HashStable_Generic};
@@ -140,7 +141,7 @@ pub struct ReprOptions {
     /// hash without loss, but it does pay the price of being larger.
     /// Everything's a tradeoff, a 64-bit seed should be sufficient for our
     /// purposes (primarily `-Z randomize-layout`)
-    pub field_shuffle_seed: u64,
+    pub field_shuffle_seed: Hash64,
 }
 
 impl ReprOptions {
@@ -1727,7 +1728,7 @@ pub struct LayoutData<FieldIdx: Idx, VariantIdx: Idx> {
     /// transmuted to `Foo<U>` we aim to create probalistically distinct seeds so that Foo can choose
     /// to reorder its fields based on that information. The current implementation is a conservative
     /// approximation of this goal.
-    pub randomization_seed: u64,
+    pub randomization_seed: Hash64,
 }
 
 impl<FieldIdx: Idx, VariantIdx: Idx> LayoutData<FieldIdx, VariantIdx> {
@@ -1781,7 +1782,7 @@ impl<FieldIdx: Idx, VariantIdx: Idx> LayoutData<FieldIdx, VariantIdx> {
             align,
             max_repr_align: None,
             unadjusted_abi_align: align.abi,
-            randomization_seed,
+            randomization_seed: Hash64::new(randomization_seed),
         }
     }
 }
diff --git a/compiler/rustc_codegen_llvm/Cargo.toml b/compiler/rustc_codegen_llvm/Cargo.toml
index 94f21ac5f57..a8172270548 100644
--- a/compiler/rustc_codegen_llvm/Cargo.toml
+++ b/compiler/rustc_codegen_llvm/Cargo.toml
@@ -25,6 +25,7 @@ rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
 rustc_fs_util = { path = "../rustc_fs_util" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_llvm = { path = "../rustc_llvm" }
diff --git a/compiler/rustc_codegen_llvm/src/common.rs b/compiler/rustc_codegen_llvm/src/common.rs
index 78b3a7f8541..f17d98fa242 100644
--- a/compiler/rustc_codegen_llvm/src/common.rs
+++ b/compiler/rustc_codegen_llvm/src/common.rs
@@ -7,7 +7,8 @@ use rustc_abi::{AddressSpace, HasDataLayout};
 use rustc_ast::Mutability;
 use rustc_codegen_ssa::common::TypeKind;
 use rustc_codegen_ssa::traits::*;
-use rustc_data_structures::stable_hasher::{Hash128, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_hashes::Hash128;
 use rustc_hir::def_id::DefId;
 use rustc_middle::bug;
 use rustc_middle::mir::interpret::{ConstAllocation, GlobalAlloc, Scalar};
diff --git a/compiler/rustc_codegen_ssa/Cargo.toml b/compiler/rustc_codegen_ssa/Cargo.toml
index 2afc1efc1b3..963d9258be6 100644
--- a/compiler/rustc_codegen_ssa/Cargo.toml
+++ b/compiler/rustc_codegen_ssa/Cargo.toml
@@ -25,6 +25,7 @@ rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
 rustc_fs_util = { path = "../rustc_fs_util" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_hir_pretty = { path = "../rustc_hir_pretty" }
 rustc_incremental = { path = "../rustc_incremental" }
diff --git a/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs b/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
index 53953b089c6..84703a0a156 100644
--- a/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
+++ b/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
@@ -15,7 +15,8 @@ use std::fmt::Write;
 
 use rustc_abi::Integer;
 use rustc_data_structures::fx::FxHashSet;
-use rustc_data_structures::stable_hasher::{Hash64, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_hashes::Hash64;
 use rustc_hir::def_id::DefId;
 use rustc_hir::definitions::{DefPathData, DefPathDataName, DisambiguatedDefPathData};
 use rustc_hir::{CoroutineDesugaring, CoroutineKind, CoroutineSource, Mutability};
diff --git a/compiler/rustc_data_structures/Cargo.toml b/compiler/rustc_data_structures/Cargo.toml
index a8f83ca13e2..1705af1e210 100644
--- a/compiler/rustc_data_structures/Cargo.toml
+++ b/compiler/rustc_data_structures/Cargo.toml
@@ -18,6 +18,7 @@ rustc-rayon = { version = "0.5.1", features = ["indexmap"] }
 rustc-stable-hash = { version = "0.1.0", features = ["nightly"] }
 rustc_arena = { path = "../rustc_arena" }
 rustc_graphviz = { path = "../rustc_graphviz" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_index = { path = "../rustc_index", package = "rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_serialize = { path = "../rustc_serialize" }
diff --git a/compiler/rustc_data_structures/src/fingerprint.rs b/compiler/rustc_data_structures/src/fingerprint.rs
index 16c66824c5b..c7c0d0ab072 100644
--- a/compiler/rustc_data_structures/src/fingerprint.rs
+++ b/compiler/rustc_data_structures/src/fingerprint.rs
@@ -1,10 +1,9 @@
 use std::hash::{Hash, Hasher};
 
+use rustc_hashes::Hash64;
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 
-use crate::stable_hasher::{
-    FromStableHash, Hash64, StableHasherHash, impl_stable_traits_for_trivial_type,
-};
+use crate::stable_hasher::{FromStableHash, StableHasherHash, impl_stable_traits_for_trivial_type};
 
 #[cfg(test)]
 mod tests;
diff --git a/compiler/rustc_data_structures/src/lib.rs b/compiler/rustc_data_structures/src/lib.rs
index 6ef73debadd..66d3834d857 100644
--- a/compiler/rustc_data_structures/src/lib.rs
+++ b/compiler/rustc_data_structures/src/lib.rs
@@ -84,7 +84,6 @@ pub mod vec_cache;
 pub mod work_queue;
 
 mod atomic_ref;
-mod hashes;
 
 /// This calls the passed function while ensuring it won't be inlined into the caller.
 #[inline(never)]
diff --git a/compiler/rustc_data_structures/src/stable_hasher.rs b/compiler/rustc_data_structures/src/stable_hasher.rs
index 9cd0cc499ca..ffbe54d6206 100644
--- a/compiler/rustc_data_structures/src/stable_hasher.rs
+++ b/compiler/rustc_data_structures/src/stable_hasher.rs
@@ -10,12 +10,11 @@ use smallvec::SmallVec;
 #[cfg(test)]
 mod tests;
 
+use rustc_hashes::{Hash64, Hash128};
 pub use rustc_stable_hash::{
     FromStableHash, SipHasher128Hash as StableHasherHash, StableSipHasher128 as StableHasher,
 };
 
-pub use crate::hashes::{Hash64, Hash128};
-
 /// Something that implements `HashStable<CTX>` can be hashed in a way that is
 /// stable across multiple compilation sessions.
 ///
diff --git a/compiler/rustc_data_structures/src/tagged_ptr/tests.rs b/compiler/rustc_data_structures/src/tagged_ptr/tests.rs
index b1bdee18d6d..9c1e4cefa69 100644
--- a/compiler/rustc_data_structures/src/tagged_ptr/tests.rs
+++ b/compiler/rustc_data_structures/src/tagged_ptr/tests.rs
@@ -1,7 +1,8 @@
 use std::ptr;
 
+use rustc_hashes::Hash128;
+
 use super::*;
-use crate::hashes::Hash128;
 use crate::stable_hasher::{HashStable, StableHasher};
 
 /// A tag type used in [`TaggedRef`] tests.
diff --git a/compiler/rustc_errors/Cargo.toml b/compiler/rustc_errors/Cargo.toml
index fbb6a1cc475..434f8c1c767 100644
--- a/compiler/rustc_errors/Cargo.toml
+++ b/compiler/rustc_errors/Cargo.toml
@@ -14,6 +14,7 @@ rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_error_codes = { path = "../rustc_error_codes" }
 rustc_error_messages = { path = "../rustc_error_messages" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_lexer = { path = "../rustc_lexer" }
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 8ff5dc12596..6fce1fade26 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -58,12 +58,13 @@ pub use emitter::ColorConfig;
 use emitter::{DynEmitter, Emitter, is_case_difference, is_different};
 use rustc_data_structures::AtomicRef;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet};
-use rustc_data_structures::stable_hasher::{Hash128, StableHasher};
+use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_data_structures::sync::{DynSend, Lock};
 pub use rustc_error_messages::{
     DiagMessage, FluentBundle, LanguageIdentifier, LazyFallbackBundle, MultiSpan, SpanLabel,
     SubdiagMessage, fallback_fluent_bundle, fluent_bundle,
 };
+use rustc_hashes::Hash128;
 use rustc_lint_defs::LintExpectationId;
 pub use rustc_lint_defs::{Applicability, listify, pluralize};
 use rustc_macros::{Decodable, Encodable};
diff --git a/compiler/rustc_hashes/Cargo.toml b/compiler/rustc_hashes/Cargo.toml
new file mode 100644
index 00000000000..c2bae2fe8cb
--- /dev/null
+++ b/compiler/rustc_hashes/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "rustc_hashes"
+version = "0.0.0"
+edition = "2021"
+
+[dependencies]
+# tidy-alphabetical-start
+rustc-stable-hash = { version = "0.1.0" }
+# tidy-alphabetical-end
diff --git a/compiler/rustc_data_structures/src/hashes.rs b/compiler/rustc_hashes/src/lib.rs
index 8f4639fc2e6..3755caaaa29 100644
--- a/compiler/rustc_data_structures/src/hashes.rs
+++ b/compiler/rustc_hashes/src/lib.rs
@@ -1,6 +1,8 @@
 //! rustc encodes a lot of hashes. If hashes are stored as `u64` or `u128`, a `derive(Encodable)`
 //! will apply varint encoding to the hashes, which is less efficient than directly encoding the 8
-//! or 16 bytes of the hash.
+//! or 16 bytes of the hash. And if that hash depends on the `StableCrateHash` (which most in rustc
+//! do), the varint encoding will make the number of bytes encoded fluctuate between compiler
+//! versions.
 //!
 //! The types in this module represent 64-bit or 128-bit hashes produced by a `StableHasher`.
 //! `Hash64` and `Hash128` expose some utility functions to encourage users to not extract the inner
@@ -14,10 +16,9 @@
 use std::fmt;
 use std::ops::BitXorAssign;
 
-use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
-
-use crate::stable_hasher::{FromStableHash, StableHasherHash};
+use rustc_stable_hash::{FromStableHash, SipHasher128Hash as StableHasherHash};
 
+/// A `u64` but encoded with a fixed size; for hashes this encoding is more compact than `u64`.
 #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Default)]
 pub struct Hash64 {
     inner: u64,
@@ -35,26 +36,17 @@ impl Hash64 {
     pub fn as_u64(self) -> u64 {
         self.inner
     }
-}
 
-impl BitXorAssign<u64> for Hash64 {
     #[inline]
-    fn bitxor_assign(&mut self, rhs: u64) {
-        self.inner ^= rhs;
-    }
-}
-
-impl<S: Encoder> Encodable<S> for Hash64 {
-    #[inline]
-    fn encode(&self, s: &mut S) {
-        s.emit_raw_bytes(&self.inner.to_le_bytes());
+    pub fn wrapping_add(self, other: Self) -> Self {
+        Self { inner: self.inner.wrapping_add(other.inner) }
     }
 }
 
-impl<D: Decoder> Decodable<D> for Hash64 {
+impl BitXorAssign<u64> for Hash64 {
     #[inline]
-    fn decode(d: &mut D) -> Self {
-        Self { inner: u64::from_le_bytes(d.read_raw_bytes(8).try_into().unwrap()) }
+    fn bitxor_assign(&mut self, rhs: u64) {
+        self.inner ^= rhs;
     }
 }
 
@@ -79,6 +71,7 @@ impl fmt::LowerHex for Hash64 {
     }
 }
 
+/// A `u128` but encoded with a fixed size; for hashes this encoding is more compact than `u128`.
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Default)]
 pub struct Hash128 {
     inner: u128,
@@ -96,6 +89,11 @@ impl std::hash::Hash for Hash128 {
 
 impl Hash128 {
     #[inline]
+    pub fn new(n: u128) -> Self {
+        Self { inner: n }
+    }
+
+    #[inline]
     pub fn truncate(self) -> Hash64 {
         Hash64 { inner: self.inner as u64 }
     }
@@ -111,20 +109,6 @@ impl Hash128 {
     }
 }
 
-impl<S: Encoder> Encodable<S> for Hash128 {
-    #[inline]
-    fn encode(&self, s: &mut S) {
-        s.emit_raw_bytes(&self.inner.to_le_bytes());
-    }
-}
-
-impl<D: Decoder> Decodable<D> for Hash128 {
-    #[inline]
-    fn decode(d: &mut D) -> Self {
-        Self { inner: u128::from_le_bytes(d.read_raw_bytes(16).try_into().unwrap()) }
-    }
-}
-
 impl FromStableHash for Hash128 {
     type Hash = StableHasherHash;
 
diff --git a/compiler/rustc_hir/Cargo.toml b/compiler/rustc_hir/Cargo.toml
index 5bfc4756ec6..b1516e53173 100644
--- a/compiler/rustc_hir/Cargo.toml
+++ b/compiler/rustc_hir/Cargo.toml
@@ -10,6 +10,7 @@ rustc_abi = { path = "../rustc_abi" }
 rustc_arena = { path = "../rustc_arena" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_data_structures = { path = "../rustc_data_structures" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_serialize = { path = "../rustc_serialize" }
diff --git a/compiler/rustc_hir/src/def_path_hash_map.rs b/compiler/rustc_hir/src/def_path_hash_map.rs
index 9a6dee1e511..35c6e57b877 100644
--- a/compiler/rustc_hir/src/def_path_hash_map.rs
+++ b/compiler/rustc_hir/src/def_path_hash_map.rs
@@ -1,4 +1,4 @@
-use rustc_data_structures::stable_hasher::Hash64;
+use rustc_hashes::Hash64;
 use rustc_span::def_id::DefIndex;
 
 #[derive(Clone, Default)]
diff --git a/compiler/rustc_hir/src/definitions.rs b/compiler/rustc_hir/src/definitions.rs
index dc527240f74..08a0a5225e7 100644
--- a/compiler/rustc_hir/src/definitions.rs
+++ b/compiler/rustc_hir/src/definitions.rs
@@ -7,8 +7,9 @@
 use std::fmt::{self, Write};
 use std::hash::Hash;
 
-use rustc_data_structures::stable_hasher::{Hash64, StableHasher};
+use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_data_structures::unord::UnordMap;
+use rustc_hashes::Hash64;
 use rustc_index::IndexVec;
 use rustc_macros::{Decodable, Encodable};
 use rustc_span::{Symbol, kw, sym};
diff --git a/compiler/rustc_hir/src/tests.rs b/compiler/rustc_hir/src/tests.rs
index e0e63d183c6..0837444ffdb 100644
--- a/compiler/rustc_hir/src/tests.rs
+++ b/compiler/rustc_hir/src/tests.rs
@@ -1,6 +1,6 @@
 #![allow(rustc::symbol_intern_string_literal)]
 
-use rustc_data_structures::stable_hasher::Hash64;
+use rustc_hashes::Hash64;
 use rustc_span::def_id::{DefPathHash, StableCrateId};
 use rustc_span::edition::Edition;
 use rustc_span::{Symbol, create_session_globals_then};
diff --git a/compiler/rustc_hir_analysis/src/bounds.rs b/compiler/rustc_hir_analysis/src/bounds.rs
deleted file mode 100644
index 9b02651a8bd..00000000000
--- a/compiler/rustc_hir_analysis/src/bounds.rs
+++ /dev/null
@@ -1,100 +0,0 @@
-//! Bounds are restrictions applied to some types after they've been lowered from the HIR to the
-//! [`rustc_middle::ty`] form.
-
-use rustc_hir::LangItem;
-use rustc_middle::ty::{self, Ty, TyCtxt, Upcast};
-use rustc_span::Span;
-
-/// Collects together a list of type bounds. These lists of bounds occur in many places
-/// in Rust's syntax:
-///
-/// ```text
-/// trait Foo: Bar + Baz { }
-///            ^^^^^^^^^ supertrait list bounding the `Self` type parameter
-///
-/// fn foo<T: Bar + Baz>() { }
-///           ^^^^^^^^^ bounding the type parameter `T`
-///
-/// impl dyn Bar + Baz
-///          ^^^^^^^^^ bounding the type-erased dynamic type
-/// ```
-///
-/// Our representation is a bit mixed here -- in some cases, we
-/// include the self type (e.g., `trait_bounds`) but in others we do not
-#[derive(Default, PartialEq, Eq, Clone, Debug)]
-pub(crate) struct Bounds<'tcx> {
-    clauses: Vec<(ty::Clause<'tcx>, Span)>,
-}
-
-impl<'tcx> Bounds<'tcx> {
-    pub(crate) fn push_region_bound(
-        &mut self,
-        tcx: TyCtxt<'tcx>,
-        region: ty::PolyTypeOutlivesPredicate<'tcx>,
-        span: Span,
-    ) {
-        self.clauses
-            .push((region.map_bound(|p| ty::ClauseKind::TypeOutlives(p)).upcast(tcx), span));
-    }
-
-    pub(crate) fn push_trait_bound(
-        &mut self,
-        tcx: TyCtxt<'tcx>,
-        bound_trait_ref: ty::PolyTraitRef<'tcx>,
-        span: Span,
-        polarity: ty::PredicatePolarity,
-    ) {
-        let clause = (
-            bound_trait_ref
-                .map_bound(|trait_ref| {
-                    ty::ClauseKind::Trait(ty::TraitPredicate { trait_ref, polarity })
-                })
-                .upcast(tcx),
-            span,
-        );
-        // FIXME(-Znext-solver): We can likely remove this hack once the new trait solver lands.
-        if tcx.is_lang_item(bound_trait_ref.def_id(), LangItem::Sized) {
-            self.clauses.insert(0, clause);
-        } else {
-            self.clauses.push(clause);
-        }
-    }
-
-    pub(crate) fn push_projection_bound(
-        &mut self,
-        tcx: TyCtxt<'tcx>,
-        projection: ty::PolyProjectionPredicate<'tcx>,
-        span: Span,
-    ) {
-        self.clauses.push((
-            projection.map_bound(|proj| ty::ClauseKind::Projection(proj)).upcast(tcx),
-            span,
-        ));
-    }
-
-    pub(crate) fn push_sized(&mut self, tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, span: Span) {
-        let sized_def_id = tcx.require_lang_item(LangItem::Sized, Some(span));
-        let trait_ref = ty::TraitRef::new(tcx, sized_def_id, [ty]);
-        // Preferable to put this obligation first, since we report better errors for sized ambiguity.
-        self.clauses.insert(0, (trait_ref.upcast(tcx), span));
-    }
-
-    /// Push a `const` or `~const` bound as a `HostEffect` predicate.
-    pub(crate) fn push_const_bound(
-        &mut self,
-        tcx: TyCtxt<'tcx>,
-        bound_trait_ref: ty::PolyTraitRef<'tcx>,
-        constness: ty::BoundConstness,
-        span: Span,
-    ) {
-        if tcx.is_const_trait(bound_trait_ref.def_id()) {
-            self.clauses.push((bound_trait_ref.to_host_effect_clause(tcx, constness), span));
-        } else {
-            tcx.dcx().span_delayed_bug(span, "tried to lower {host:?} bound for non-const trait");
-        }
-    }
-
-    pub(crate) fn clauses(&self) -> impl Iterator<Item = (ty::Clause<'tcx>, Span)> + '_ {
-        self.clauses.iter().cloned()
-    }
-}
diff --git a/compiler/rustc_hir_analysis/src/collect/item_bounds.rs b/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
index 41c4cfbaa82..1c1a246cc15 100644
--- a/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
+++ b/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
@@ -13,7 +13,6 @@ use tracing::{debug, instrument};
 
 use super::ItemCtxt;
 use super::predicates_of::assert_only_contains_predicates_from;
-use crate::bounds::Bounds;
 use crate::hir_ty_lowering::{HirTyLowerer, PredicateFilter};
 
 /// For associated types we include both bounds written on the type
@@ -38,7 +37,7 @@ fn associated_type_bounds<'tcx>(
         );
 
         let icx = ItemCtxt::new(tcx, assoc_item_def_id);
-        let mut bounds = Bounds::default();
+        let mut bounds = Vec::new();
         icx.lowerer().lower_bounds(item_ty, hir_bounds, &mut bounds, ty::List::empty(), filter);
         // Associated types are implicitly sized unless a `?Sized` bound is found
         match filter {
@@ -68,7 +67,7 @@ fn associated_type_bounds<'tcx>(
                 )
             });
 
-        let all_bounds = tcx.arena.alloc_from_iter(bounds.clauses().chain(bounds_from_parent));
+        let all_bounds = tcx.arena.alloc_from_iter(bounds.into_iter().chain(bounds_from_parent));
         debug!(
             "associated_type_bounds({}) = {:?}",
             tcx.def_path_str(assoc_item_def_id.to_def_id()),
@@ -327,7 +326,7 @@ fn opaque_type_bounds<'tcx>(
 ) -> &'tcx [(ty::Clause<'tcx>, Span)] {
     ty::print::with_reduced_queries!({
         let icx = ItemCtxt::new(tcx, opaque_def_id);
-        let mut bounds = Bounds::default();
+        let mut bounds = Vec::new();
         icx.lowerer().lower_bounds(item_ty, hir_bounds, &mut bounds, ty::List::empty(), filter);
         // Opaque types are implicitly sized unless a `?Sized` bound is found
         match filter {
@@ -343,7 +342,7 @@ fn opaque_type_bounds<'tcx>(
         }
         debug!(?bounds);
 
-        tcx.arena.alloc_from_iter(bounds.clauses())
+        tcx.arena.alloc_slice(&bounds)
     })
 }
 
diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
index d94383d6f3d..70e7451a5fb 100644
--- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
@@ -13,7 +13,6 @@ use rustc_span::{DUMMY_SP, Ident, Span};
 use tracing::{debug, instrument, trace};
 
 use super::item_bounds::explicit_item_bounds_with_filter;
-use crate::bounds::Bounds;
 use crate::collect::ItemCtxt;
 use crate::constrained_generic_params as cgp;
 use crate::delegation::inherit_predicates_for_delegation_item;
@@ -178,7 +177,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
     // on a trait we must also consider the bounds that follow the trait's name,
     // like `trait Foo: A + B + C`.
     if let Some(self_bounds) = is_trait {
-        let mut bounds = Bounds::default();
+        let mut bounds = Vec::new();
         icx.lowerer().lower_bounds(
             tcx.types.self_param,
             self_bounds,
@@ -186,7 +185,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
             ty::List::empty(),
             PredicateFilter::All,
         );
-        predicates.extend(bounds.clauses());
+        predicates.extend(bounds);
     }
 
     // In default impls, we can assume that the self type implements
@@ -209,7 +208,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
             GenericParamKind::Lifetime { .. } => (),
             GenericParamKind::Type { .. } => {
                 let param_ty = icx.lowerer().lower_ty_param(param.hir_id);
-                let mut bounds = Bounds::default();
+                let mut bounds = Vec::new();
                 // Params are implicitly sized unless a `?Sized` bound is found
                 icx.lowerer().add_sized_bound(
                     &mut bounds,
@@ -219,7 +218,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
                     param.span,
                 );
                 trace!(?bounds);
-                predicates.extend(bounds.clauses());
+                predicates.extend(bounds);
                 trace!(?predicates);
             }
             hir::GenericParamKind::Const { .. } => {
@@ -264,7 +263,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
                     }
                 }
 
-                let mut bounds = Bounds::default();
+                let mut bounds = Vec::new();
                 icx.lowerer().lower_bounds(
                     ty,
                     bound_pred.bounds,
@@ -272,7 +271,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
                     bound_vars,
                     PredicateFilter::All,
                 );
-                predicates.extend(bounds.clauses());
+                predicates.extend(bounds);
             }
 
             hir::WherePredicateKind::RegionPredicate(region_pred) => {
@@ -627,7 +626,7 @@ pub(super) fn implied_predicates_with_filter<'tcx>(
     let icx = ItemCtxt::new(tcx, trait_def_id);
 
     let self_param_ty = tcx.types.self_param;
-    let mut bounds = Bounds::default();
+    let mut bounds = Vec::new();
     icx.lowerer().lower_bounds(self_param_ty, superbounds, &mut bounds, ty::List::empty(), filter);
 
     let where_bounds_that_match =
@@ -635,7 +634,7 @@ pub(super) fn implied_predicates_with_filter<'tcx>(
 
     // Combine the two lists to form the complete set of superbounds:
     let implied_bounds =
-        &*tcx.arena.alloc_from_iter(bounds.clauses().chain(where_bounds_that_match));
+        &*tcx.arena.alloc_from_iter(bounds.into_iter().chain(where_bounds_that_match));
     debug!(?implied_bounds);
 
     // Now require that immediate supertraits are lowered, which will, in
@@ -904,7 +903,7 @@ impl<'tcx> ItemCtxt<'tcx> {
         param_def_id: LocalDefId,
         filter: PredicateFilter,
     ) -> Vec<(ty::Clause<'tcx>, Span)> {
-        let mut bounds = Bounds::default();
+        let mut bounds = Vec::new();
 
         for predicate in hir_generics.predicates {
             let hir_id = predicate.hir_id;
@@ -938,7 +937,7 @@ impl<'tcx> ItemCtxt<'tcx> {
             );
         }
 
-        bounds.clauses().collect()
+        bounds
     }
 }
 
@@ -1007,7 +1006,7 @@ pub(super) fn const_conditions<'tcx>(
     };
 
     let icx = ItemCtxt::new(tcx, def_id);
-    let mut bounds = Bounds::default();
+    let mut bounds = Vec::new();
 
     for pred in generics.predicates {
         match pred.kind {
@@ -1027,12 +1026,12 @@ pub(super) fn const_conditions<'tcx>(
     }
 
     if let Some((def_id, supertraits)) = trait_def_id_and_supertraits {
-        bounds.push_const_bound(
-            tcx,
-            ty::Binder::dummy(ty::TraitRef::identity(tcx, def_id.to_def_id())),
-            ty::BoundConstness::Maybe,
+        // We've checked above that the trait is conditionally const.
+        bounds.push((
+            ty::Binder::dummy(ty::TraitRef::identity(tcx, def_id.to_def_id()))
+                .to_host_effect_clause(tcx, ty::BoundConstness::Maybe),
             DUMMY_SP,
-        );
+        ));
 
         icx.lowerer().lower_bounds(
             tcx.types.self_param,
@@ -1045,7 +1044,7 @@ pub(super) fn const_conditions<'tcx>(
 
     ty::ConstConditions {
         parent: has_parent.then(|| tcx.local_parent(def_id).to_def_id()),
-        predicates: tcx.arena.alloc_from_iter(bounds.clauses().map(|(clause, span)| {
+        predicates: tcx.arena.alloc_from_iter(bounds.into_iter().map(|(clause, span)| {
             (
                 clause.kind().map_bound(|clause| match clause {
                     ty::ClauseKind::HostEffect(ty::HostEffectPredicate {
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs
index ef6167907b5..75c97001c32 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs
@@ -8,7 +8,7 @@ use rustc_hir::HirId;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_middle::bug;
-use rustc_middle::ty::{self as ty, IsSuggestable, Ty, TyCtxt};
+use rustc_middle::ty::{self as ty, IsSuggestable, Ty, TyCtxt, Upcast};
 use rustc_span::{ErrorGuaranteed, Ident, Span, Symbol, kw, sym};
 use rustc_trait_selection::traits;
 use rustc_type_ir::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor};
@@ -16,7 +16,6 @@ use smallvec::SmallVec;
 use tracing::{debug, instrument};
 
 use super::errors::GenericsArgsErrExtend;
-use crate::bounds::Bounds;
 use crate::errors;
 use crate::hir_ty_lowering::{
     AssocItemQSelf, FeedConstTy, HirTyLowerer, PredicateFilter, RegionInferReason,
@@ -28,7 +27,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     /// Doesn't add the bound if the HIR bounds contain any of `Sized`, `?Sized` or `!Sized`.
     pub(crate) fn add_sized_bound(
         &self,
-        bounds: &mut Bounds<'tcx>,
+        bounds: &mut Vec<(ty::Clause<'tcx>, Span)>,
         self_ty: Ty<'tcx>,
         hir_bounds: &'tcx [hir::GenericBound<'tcx>],
         self_ty_where_predicates: Option<(LocalDefId, &'tcx [hir::WherePredicate<'tcx>])>,
@@ -113,10 +112,12 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         if seen_sized_unbound || seen_negative_sized_bound || seen_positive_sized_bound {
             // There was in fact a `?Sized`, `!Sized` or explicit `Sized` bound;
             // we don't need to do anything.
-        } else if sized_def_id.is_some() {
+        } else if let Some(sized_def_id) = sized_def_id {
             // There was no `?Sized`, `!Sized` or explicit `Sized` bound;
             // add `Sized` if it's available.
-            bounds.push_sized(tcx, self_ty, span);
+            let trait_ref = ty::TraitRef::new(tcx, sized_def_id, [self_ty]);
+            // Preferable to put this obligation first, since we report better errors for sized ambiguity.
+            bounds.insert(0, (trait_ref.upcast(tcx), span));
         }
     }
 
@@ -146,7 +147,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         &self,
         param_ty: Ty<'tcx>,
         hir_bounds: I,
-        bounds: &mut Bounds<'tcx>,
+        bounds: &mut Vec<(ty::Clause<'tcx>, Span)>,
         bound_vars: &'tcx ty::List<ty::BoundVariableKind>,
         predicate_filter: PredicateFilter,
     ) where
@@ -189,14 +190,11 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                     }
 
                     let region = self.lower_lifetime(lifetime, RegionInferReason::OutlivesBound);
-                    bounds.push_region_bound(
-                        self.tcx(),
-                        ty::Binder::bind_with_vars(
-                            ty::OutlivesPredicate(param_ty, region),
-                            bound_vars,
-                        ),
-                        lifetime.ident.span,
+                    let bound = ty::Binder::bind_with_vars(
+                        ty::ClauseKind::TypeOutlives(ty::OutlivesPredicate(param_ty, region)),
+                        bound_vars,
                     );
+                    bounds.push((bound.upcast(self.tcx()), lifetime.ident.span));
                 }
                 hir::GenericBound::Use(..) => {
                     // We don't actually lower `use` into the type layer.
@@ -219,7 +217,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         hir_ref_id: hir::HirId,
         trait_ref: ty::PolyTraitRef<'tcx>,
         constraint: &hir::AssocItemConstraint<'tcx>,
-        bounds: &mut Bounds<'tcx>,
+        bounds: &mut Vec<(ty::Clause<'tcx>, Span)>,
         duplicates: &mut FxIndexMap<DefId, Span>,
         path_span: Span,
         predicate_filter: PredicateFilter,
@@ -389,14 +387,13 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                     PredicateFilter::All
                     | PredicateFilter::SelfOnly
                     | PredicateFilter::SelfAndAssociatedTypeBounds => {
-                        bounds.push_projection_bound(
-                            tcx,
-                            projection_term.map_bound(|projection_term| ty::ProjectionPredicate {
+                        let bound = projection_term.map_bound(|projection_term| {
+                            ty::ClauseKind::Projection(ty::ProjectionPredicate {
                                 projection_term,
                                 term,
-                            }),
-                            constraint.span,
-                        );
+                            })
+                        });
+                        bounds.push((bound.upcast(tcx), constraint.span));
                     }
                     // SelfTraitThatDefines is only interested in trait predicates.
                     PredicateFilter::SelfTraitThatDefines(_) => {}
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/dyn_compatibility.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/dyn_compatibility.rs
index a8b37fa5054..830dca0d3cd 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/dyn_compatibility.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/dyn_compatibility.rs
@@ -17,7 +17,6 @@ use smallvec::{SmallVec, smallvec};
 use tracing::{debug, instrument};
 
 use super::HirTyLowerer;
-use crate::bounds::Bounds;
 use crate::hir_ty_lowering::{
     GenericArgCountMismatch, GenericArgCountResult, PredicateFilter, RegionInferReason,
 };
@@ -36,7 +35,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         let tcx = self.tcx();
         let dummy_self = tcx.types.trait_object_dummy_self;
 
-        let mut user_written_bounds = Bounds::default();
+        let mut user_written_bounds = Vec::new();
         let mut potential_assoc_types = Vec::new();
         for trait_bound in hir_bounds.iter() {
             if let hir::BoundPolarity::Maybe(_) = trait_bound.modifiers.polarity {
@@ -60,15 +59,17 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         }
 
         let (trait_bounds, mut projection_bounds) =
-            traits::expand_trait_aliases(tcx, user_written_bounds.clauses());
+            traits::expand_trait_aliases(tcx, user_written_bounds.iter().copied());
         let (regular_traits, mut auto_traits): (Vec<_>, Vec<_>) = trait_bounds
             .into_iter()
             .partition(|(trait_ref, _)| !tcx.trait_is_auto(trait_ref.def_id()));
 
         // We  don't support empty trait objects.
         if regular_traits.is_empty() && auto_traits.is_empty() {
-            let guar =
-                self.report_trait_object_with_no_traits_error(span, user_written_bounds.clauses());
+            let guar = self.report_trait_object_with_no_traits_error(
+                span,
+                user_written_bounds.iter().copied(),
+            );
             return Ty::new_error(tcx, guar);
         }
         // We don't support >1 principal
@@ -84,7 +85,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         // Check that there are no gross dyn-compatibility violations;
         // most importantly, that the supertraits don't contain `Self`,
         // to avoid ICEs.
-        for (clause, span) in user_written_bounds.clauses() {
+        for (clause, span) in user_written_bounds {
             if let Some(trait_pred) = clause.as_trait_clause() {
                 let violations =
                     hir_ty_lowering_dyn_compatibility_violations(tcx, trait_pred.def_id());
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
index d5ccbdc11c8..7dce8b9b60f 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
@@ -49,9 +49,9 @@ use rustc_span::{DUMMY_SP, Ident, Span, Symbol, kw};
 use rustc_trait_selection::infer::InferCtxtExt;
 use rustc_trait_selection::traits::wf::object_region_bounds;
 use rustc_trait_selection::traits::{self, ObligationCtxt};
+use rustc_type_ir::Upcast;
 use tracing::{debug, instrument};
 
-use crate::bounds::Bounds;
 use crate::check::check_abi_fn_ptr;
 use crate::errors::{AmbiguousLifetimeBound, BadReturnTypeNotation, InvalidBaseType};
 use crate::hir_ty_lowering::errors::{GenericsArgsErrExtend, prohibit_assoc_item_constraint};
@@ -691,7 +691,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         constness: hir::BoundConstness,
         polarity: hir::BoundPolarity,
         self_ty: Ty<'tcx>,
-        bounds: &mut Bounds<'tcx>,
+        bounds: &mut Vec<(ty::Clause<'tcx>, Span)>,
         predicate_filter: PredicateFilter,
     ) -> GenericArgCountResult {
         let trait_def_id = trait_ref.trait_def_id().unwrap_or_else(|| FatalError.raise());
@@ -720,6 +720,8 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             bound_vars,
         );
 
+        debug!(?poly_trait_ref);
+
         let polarity = match polarity {
             rustc_ast::BoundPolarity::Positive => ty::PredicatePolarity::Positive,
             rustc_ast::BoundPolarity::Negative(_) => ty::PredicatePolarity::Negative,
@@ -741,6 +743,26 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             }
         };
 
+        // We deal with const conditions later.
+        match predicate_filter {
+            PredicateFilter::All
+            | PredicateFilter::SelfOnly
+            | PredicateFilter::SelfTraitThatDefines(..)
+            | PredicateFilter::SelfAndAssociatedTypeBounds => {
+                let bound = poly_trait_ref.map_bound(|trait_ref| {
+                    ty::ClauseKind::Trait(ty::TraitPredicate { trait_ref, polarity })
+                });
+                let bound = (bound.upcast(tcx), span);
+                // FIXME(-Znext-solver): We can likely remove this hack once the new trait solver lands.
+                if tcx.is_lang_item(trait_def_id, rustc_hir::LangItem::Sized) {
+                    bounds.insert(0, bound);
+                } else {
+                    bounds.push(bound);
+                }
+            }
+            PredicateFilter::ConstIfConst | PredicateFilter::SelfConstIfConst => {}
+        }
+
         if let hir::BoundConstness::Always(span) | hir::BoundConstness::Maybe(span) = constness
             && !self.tcx().is_const_trait(trait_def_id)
         {
@@ -765,58 +787,53 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 suggestion_pre,
                 suggestion,
             });
-        }
-
-        match predicate_filter {
-            // This is only concerned with trait predicates.
-            PredicateFilter::SelfTraitThatDefines(..) => {
-                bounds.push_trait_bound(tcx, poly_trait_ref, span, polarity);
-            }
-            PredicateFilter::All
-            | PredicateFilter::SelfOnly
-            | PredicateFilter::SelfAndAssociatedTypeBounds => {
-                debug!(?poly_trait_ref);
-                bounds.push_trait_bound(tcx, poly_trait_ref, span, polarity);
-
-                match constness {
-                    hir::BoundConstness::Always(span) => {
-                        if polarity == ty::PredicatePolarity::Positive {
-                            bounds.push_const_bound(
-                                tcx,
-                                poly_trait_ref,
-                                ty::BoundConstness::Const,
-                                span,
-                            );
+        } else {
+            match predicate_filter {
+                // This is only concerned with trait predicates.
+                PredicateFilter::SelfTraitThatDefines(..) => {}
+                PredicateFilter::All
+                | PredicateFilter::SelfOnly
+                | PredicateFilter::SelfAndAssociatedTypeBounds => {
+                    match constness {
+                        hir::BoundConstness::Always(span) => {
+                            if polarity == ty::PredicatePolarity::Positive {
+                                bounds.push((
+                                    poly_trait_ref
+                                        .to_host_effect_clause(tcx, ty::BoundConstness::Const),
+                                    span,
+                                ));
+                            }
                         }
+                        hir::BoundConstness::Maybe(_) => {
+                            // We don't emit a const bound here, since that would mean that we
+                            // unconditionally need to prove a `HostEffect` predicate, even when
+                            // the predicates are being instantiated in a non-const context. This
+                            // is instead handled in the `const_conditions` query.
+                        }
+                        hir::BoundConstness::Never => {}
                     }
-                    hir::BoundConstness::Maybe(_) => {
-                        // We don't emit a const bound here, since that would mean that we
-                        // unconditionally need to prove a `HostEffect` predicate, even when
-                        // the predicates are being instantiated in a non-const context. This
-                        // is instead handled in the `const_conditions` query.
-                    }
-                    hir::BoundConstness::Never => {}
                 }
-            }
-            // On the flip side, when filtering `ConstIfConst` bounds, we only need to convert
-            // `~const` bounds. All other predicates are handled in their respective queries.
-            //
-            // Note that like `PredicateFilter::SelfOnly`, we don't need to do any filtering
-            // here because we only call this on self bounds, and deal with the recursive case
-            // in `lower_assoc_item_constraint`.
-            PredicateFilter::ConstIfConst | PredicateFilter::SelfConstIfConst => match constness {
-                hir::BoundConstness::Maybe(span) => {
-                    if polarity == ty::PredicatePolarity::Positive {
-                        bounds.push_const_bound(
-                            tcx,
-                            poly_trait_ref,
-                            ty::BoundConstness::Maybe,
-                            span,
-                        );
+                // On the flip side, when filtering `ConstIfConst` bounds, we only need to convert
+                // `~const` bounds. All other predicates are handled in their respective queries.
+                //
+                // Note that like `PredicateFilter::SelfOnly`, we don't need to do any filtering
+                // here because we only call this on self bounds, and deal with the recursive case
+                // in `lower_assoc_item_constraint`.
+                PredicateFilter::ConstIfConst | PredicateFilter::SelfConstIfConst => {
+                    match constness {
+                        hir::BoundConstness::Maybe(span) => {
+                            if polarity == ty::PredicatePolarity::Positive {
+                                bounds.push((
+                                    poly_trait_ref
+                                        .to_host_effect_clause(tcx, ty::BoundConstness::Maybe),
+                                    span,
+                                ));
+                            }
+                        }
+                        hir::BoundConstness::Always(_) | hir::BoundConstness::Never => {}
                     }
                 }
-                hir::BoundConstness::Always(_) | hir::BoundConstness::Never => {}
-            },
+            }
         }
 
         let mut dup_constraints = FxIndexMap::default();
@@ -2382,7 +2399,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 // Impl trait in bindings lower as an infer var with additional
                 // set of type bounds.
                 let self_ty = self.ty_infer(None, hir_ty.span);
-                let mut bounds = Bounds::default();
+                let mut bounds = Vec::new();
                 self.lower_bounds(
                     self_ty,
                     hir_bounds.iter(),
@@ -2390,11 +2407,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                     ty::List::empty(),
                     PredicateFilter::All,
                 );
-                self.register_trait_ascription_bounds(
-                    bounds.clauses().collect(),
-                    hir_ty.hir_id,
-                    hir_ty.span,
-                );
+                self.register_trait_ascription_bounds(bounds, hir_ty.hir_id, hir_ty.span);
                 self_ty
             }
             // If we encounter a type relative path with RTN generics, then it must have
diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
index 8a529e9c686..886360dfb6c 100644
--- a/compiler/rustc_hir_analysis/src/lib.rs
+++ b/compiler/rustc_hir_analysis/src/lib.rs
@@ -80,7 +80,6 @@ This API is completely unstable and subject to change.
 pub mod check;
 
 pub mod autoderef;
-mod bounds;
 mod check_unused;
 mod coherence;
 mod collect;
diff --git a/compiler/rustc_middle/Cargo.toml b/compiler/rustc_middle/Cargo.toml
index de722e62043..1b6a174c093 100644
--- a/compiler/rustc_middle/Cargo.toml
+++ b/compiler/rustc_middle/Cargo.toml
@@ -22,6 +22,7 @@ rustc_errors = { path = "../rustc_errors" }
 rustc_feature = { path = "../rustc_feature" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
 rustc_graphviz = { path = "../rustc_graphviz" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_hir_pretty = { path = "../rustc_hir_pretty" }
 rustc_index = { path = "../rustc_index" }
diff --git a/compiler/rustc_middle/src/mir/mono.rs b/compiler/rustc_middle/src/mir/mono.rs
index d4a9aac3733..4a21b6ad237 100644
--- a/compiler/rustc_middle/src/mir/mono.rs
+++ b/compiler/rustc_middle/src/mir/mono.rs
@@ -6,8 +6,9 @@ use rustc_attr_parsing::InlineAttr;
 use rustc_data_structures::base_n::{BaseNString, CASE_INSENSITIVE, ToBaseN};
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::FxIndexMap;
-use rustc_data_structures::stable_hasher::{Hash128, HashStable, StableHasher, ToStableHashKey};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher, ToStableHashKey};
 use rustc_data_structures::unord::UnordMap;
+use rustc_hashes::Hash128;
 use rustc_hir::ItemId;
 use rustc_hir::def_id::{CrateNum, DefId, DefIdSet, LOCAL_CRATE};
 use rustc_index::Idx;
diff --git a/compiler/rustc_middle/src/ty/generic_args.rs b/compiler/rustc_middle/src/ty/generic_args.rs
index fd84d75b53f..56a38a84c9f 100644
--- a/compiler/rustc_middle/src/ty/generic_args.rs
+++ b/compiler/rustc_middle/src/ty/generic_args.rs
@@ -495,7 +495,7 @@ impl<'tcx> GenericArgs<'tcx> {
         self.iter().filter_map(|k| k.as_const())
     }
 
-    /// Returns generic arguments that are not lifetimes or host effect params.
+    /// Returns generic arguments that are not lifetimes.
     #[inline]
     pub fn non_erasable_generics(
         &'tcx self,
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index e5a4e38c875..bbb8a9fa671 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -11,6 +11,7 @@ use rustc_error_messages::DiagMessage;
 use rustc_errors::{
     Diag, DiagArgValue, DiagCtxtHandle, Diagnostic, EmissionGuarantee, IntoDiagArg, Level,
 };
+use rustc_hashes::Hash64;
 use rustc_hir::LangItem;
 use rustc_hir::def_id::DefId;
 use rustc_index::IndexVec;
@@ -778,7 +779,7 @@ where
                     size: Size::ZERO,
                     max_repr_align: None,
                     unadjusted_abi_align: tcx.data_layout.i8_align.abi,
-                    randomization_seed: 0,
+                    randomization_seed: Hash64::ZERO,
                 })
             }
 
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 04519008711..7beb6d84044 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -1487,8 +1487,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
         // Generate a deterministically-derived seed from the item's path hash
         // to allow for cross-crate compilation to actually work
-        let mut field_shuffle_seed =
-            self.def_path_hash(did.to_def_id()).0.to_smaller_hash().as_u64();
+        let mut field_shuffle_seed = self.def_path_hash(did.to_def_id()).0.to_smaller_hash();
 
         // If the user defined a custom seed for layout randomization, xor the item's
         // path hash with the user defined seed, this will allowing determinism while
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index 94bd359f6eb..88d57498542 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -5,9 +5,10 @@ use std::{fmt, iter};
 use rustc_abi::{ExternAbi, Float, Integer, IntegerType, Size};
 use rustc_apfloat::Float as _;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_data_structures::stable_hasher::{Hash128, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_errors::ErrorGuaranteed;
+use rustc_hashes::Hash128;
 use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Res};
 use rustc_hir::def_id::{CrateNum, DefId, LocalDefId};
diff --git a/compiler/rustc_query_impl/Cargo.toml b/compiler/rustc_query_impl/Cargo.toml
index 8b0cc9d726b..fd1d21b6a89 100644
--- a/compiler/rustc_query_impl/Cargo.toml
+++ b/compiler/rustc_query_impl/Cargo.toml
@@ -8,6 +8,7 @@ edition = "2021"
 measureme = "11"
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_middle = { path = "../rustc_middle" }
diff --git a/compiler/rustc_query_impl/src/plumbing.rs b/compiler/rustc_query_impl/src/plumbing.rs
index e95c186f6b6..f98d6421307 100644
--- a/compiler/rustc_query_impl/src/plumbing.rs
+++ b/compiler/rustc_query_impl/src/plumbing.rs
@@ -4,10 +4,11 @@
 
 use std::num::NonZero;
 
-use rustc_data_structures::stable_hasher::{Hash64, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::Lock;
 use rustc_data_structures::unord::UnordMap;
 use rustc_errors::DiagInner;
+use rustc_hashes::Hash64;
 use rustc_index::Idx;
 use rustc_middle::bug;
 use rustc_middle::dep_graph::{
diff --git a/compiler/rustc_query_system/Cargo.toml b/compiler/rustc_query_system/Cargo.toml
index a42329b4614..d9560f3eb0f 100644
--- a/compiler/rustc_query_system/Cargo.toml
+++ b/compiler/rustc_query_system/Cargo.toml
@@ -13,6 +13,7 @@ rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_feature = { path = "../rustc_feature" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
diff --git a/compiler/rustc_query_system/src/query/mod.rs b/compiler/rustc_query_system/src/query/mod.rs
index 82c51193a19..7490a3f3503 100644
--- a/compiler/rustc_query_system/src/query/mod.rs
+++ b/compiler/rustc_query_system/src/query/mod.rs
@@ -11,9 +11,9 @@ mod caches;
 pub use self::caches::{DefIdCache, DefaultCache, QueryCache, SingleCache, VecCache};
 
 mod config;
-use rustc_data_structures::stable_hasher::Hash64;
 use rustc_data_structures::sync::Lock;
 use rustc_errors::DiagInner;
+use rustc_hashes::Hash64;
 use rustc_hir::def::DefKind;
 use rustc_macros::{Decodable, Encodable};
 use rustc_span::Span;
diff --git a/compiler/rustc_serialize/Cargo.toml b/compiler/rustc_serialize/Cargo.toml
index 8bf98c16361..a6815c7a447 100644
--- a/compiler/rustc_serialize/Cargo.toml
+++ b/compiler/rustc_serialize/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2021"
 [dependencies]
 # tidy-alphabetical-start
 indexmap = "2.0.0"
+rustc_hashes = { path = "../rustc_hashes" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"
 # tidy-alphabetical-end
diff --git a/compiler/rustc_serialize/src/serialize.rs b/compiler/rustc_serialize/src/serialize.rs
index db8555edd0f..1eefd76f92b 100644
--- a/compiler/rustc_serialize/src/serialize.rs
+++ b/compiler/rustc_serialize/src/serialize.rs
@@ -10,6 +10,7 @@ use std::path;
 use std::rc::Rc;
 use std::sync::Arc;
 
+use rustc_hashes::{Hash64, Hash128};
 use smallvec::{Array, SmallVec};
 use thin_vec::ThinVec;
 
@@ -716,3 +717,31 @@ impl<D: Decoder, T: Decodable<D>> Decodable<D> for Arc<[T]> {
         vec.into()
     }
 }
+
+impl<S: Encoder> Encodable<S> for Hash64 {
+    #[inline]
+    fn encode(&self, s: &mut S) {
+        s.emit_raw_bytes(&self.as_u64().to_le_bytes());
+    }
+}
+
+impl<S: Encoder> Encodable<S> for Hash128 {
+    #[inline]
+    fn encode(&self, s: &mut S) {
+        s.emit_raw_bytes(&self.as_u128().to_le_bytes());
+    }
+}
+
+impl<D: Decoder> Decodable<D> for Hash64 {
+    #[inline]
+    fn decode(d: &mut D) -> Self {
+        Self::new(u64::from_le_bytes(d.read_raw_bytes(8).try_into().unwrap()))
+    }
+}
+
+impl<D: Decoder> Decodable<D> for Hash128 {
+    #[inline]
+    fn decode(d: &mut D) -> Self {
+        Self::new(u128::from_le_bytes(d.read_raw_bytes(16).try_into().unwrap()))
+    }
+}
diff --git a/compiler/rustc_session/Cargo.toml b/compiler/rustc_session/Cargo.toml
index b9c535df4bd..31892c13438 100644
--- a/compiler/rustc_session/Cargo.toml
+++ b/compiler/rustc_session/Cargo.toml
@@ -14,6 +14,7 @@ rustc_errors = { path = "../rustc_errors" }
 rustc_feature = { path = "../rustc_feature" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
 rustc_fs_util = { path = "../rustc_fs_util" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_lint_defs = { path = "../rustc_lint_defs" }
 rustc_macros = { path = "../rustc_macros" }
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 7d473b86ff5..85ef69ea2b7 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -2934,9 +2934,9 @@ pub(crate) mod dep_tracking {
 
     use rustc_abi::Align;
     use rustc_data_structures::fx::FxIndexMap;
-    use rustc_data_structures::stable_hasher::Hash64;
     use rustc_errors::LanguageIdentifier;
     use rustc_feature::UnstableFeatures;
+    use rustc_hashes::Hash64;
     use rustc_span::RealFileName;
     use rustc_span::edition::Edition;
     use rustc_target::spec::{
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 35819f896c5..351dad3f3e4 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -7,9 +7,9 @@ use std::str;
 use rustc_abi::Align;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::profiling::TimePassesFormat;
-use rustc_data_structures::stable_hasher::Hash64;
 use rustc_errors::{ColorConfig, LanguageIdentifier, TerminalUrl};
 use rustc_feature::UnstableFeatures;
+use rustc_hashes::Hash64;
 use rustc_macros::{Decodable, Encodable};
 use rustc_span::edition::Edition;
 use rustc_span::{RealFileName, SourceFileHashAlgorithm};
diff --git a/compiler/rustc_span/Cargo.toml b/compiler/rustc_span/Cargo.toml
index 781fe6a11fe..991c75cc98d 100644
--- a/compiler/rustc_span/Cargo.toml
+++ b/compiler/rustc_span/Cargo.toml
@@ -12,6 +12,7 @@ itoa = "1.0"
 md5 = { package = "md-5", version = "0.10.0" }
 rustc_arena = { path = "../rustc_arena" }
 rustc_data_structures = { path = "../rustc_data_structures" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_serialize = { path = "../rustc_serialize" }
diff --git a/compiler/rustc_span/src/def_id.rs b/compiler/rustc_span/src/def_id.rs
index f61ce37131e..641bac88ad0 100644
--- a/compiler/rustc_span/src/def_id.rs
+++ b/compiler/rustc_span/src/def_id.rs
@@ -3,10 +3,9 @@ use std::hash::{BuildHasherDefault, Hash, Hasher};
 
 use rustc_data_structures::AtomicRef;
 use rustc_data_structures::fingerprint::Fingerprint;
-use rustc_data_structures::stable_hasher::{
-    Hash64, HashStable, StableHasher, StableOrd, ToStableHashKey,
-};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher, StableOrd, ToStableHashKey};
 use rustc_data_structures::unhash::Unhasher;
+use rustc_hashes::Hash64;
 use rustc_index::Idx;
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
 use rustc_serialize::{Decodable, Encodable};
diff --git a/compiler/rustc_span/src/hygiene.rs b/compiler/rustc_span/src/hygiene.rs
index 2910bcdf51d..9bf1d305e54 100644
--- a/compiler/rustc_span/src/hygiene.rs
+++ b/compiler/rustc_span/src/hygiene.rs
@@ -33,9 +33,10 @@ use std::sync::Arc;
 
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_data_structures::stable_hasher::{Hash64, HashStable, HashingControls, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, HashingControls, StableHasher};
 use rustc_data_structures::sync::{Lock, WorkerLocal};
 use rustc_data_structures::unhash::UnhashMap;
+use rustc_hashes::Hash64;
 use rustc_index::IndexVec;
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index 0e146baef37..695edc956cd 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -87,9 +87,10 @@ use std::sync::Arc;
 use std::{fmt, iter};
 
 use md5::{Digest, Md5};
-use rustc_data_structures::stable_hasher::{Hash64, Hash128, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::{FreezeLock, FreezeWriteGuard, Lock};
 use rustc_data_structures::unord::UnordMap;
+use rustc_hashes::{Hash64, Hash128};
 use sha1::Sha1;
 use sha2::Sha256;
 
diff --git a/compiler/rustc_symbol_mangling/Cargo.toml b/compiler/rustc_symbol_mangling/Cargo.toml
index 1fb647cab5b..4c51c908f54 100644
--- a/compiler/rustc_symbol_mangling/Cargo.toml
+++ b/compiler/rustc_symbol_mangling/Cargo.toml
@@ -11,6 +11,7 @@ rustc-demangle = "0.1.21"
 rustc_abi = { path = "../rustc_abi" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_session = { path = "../rustc_session" }
diff --git a/compiler/rustc_symbol_mangling/src/hashed.rs b/compiler/rustc_symbol_mangling/src/hashed.rs
index 07c5f544792..e965e6a7d53 100644
--- a/compiler/rustc_symbol_mangling/src/hashed.rs
+++ b/compiler/rustc_symbol_mangling/src/hashed.rs
@@ -1,6 +1,7 @@
 use std::fmt::Write;
 
-use rustc_data_structures::stable_hasher::{Hash64, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_hashes::Hash64;
 use rustc_hir::def_id::CrateNum;
 use rustc_middle::ty::{Instance, TyCtxt};
 
diff --git a/compiler/rustc_symbol_mangling/src/legacy.rs b/compiler/rustc_symbol_mangling/src/legacy.rs
index 8ae35572d01..88754f1f15b 100644
--- a/compiler/rustc_symbol_mangling/src/legacy.rs
+++ b/compiler/rustc_symbol_mangling/src/legacy.rs
@@ -1,7 +1,8 @@
 use std::fmt::{self, Write};
 use std::mem::{self, discriminant};
 
-use rustc_data_structures::stable_hasher::{Hash64, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_hashes::Hash64;
 use rustc_hir::def_id::{CrateNum, DefId};
 use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
 use rustc_middle::bug;
diff --git a/compiler/rustc_target/src/spec/targets/i586_pc_windows_msvc.rs b/compiler/rustc_target/src/spec/targets/i586_pc_windows_msvc.rs
index dd38f86bced..394e6f9e6bf 100644
--- a/compiler/rustc_target/src/spec/targets/i586_pc_windows_msvc.rs
+++ b/compiler/rustc_target/src/spec/targets/i586_pc_windows_msvc.rs
@@ -2,6 +2,7 @@ use crate::spec::Target;
 
 pub(crate) fn target() -> Target {
     let mut base = super::i686_pc_windows_msvc::target();
+    base.rustc_abi = None; // overwrite the SSE2 ABI set by the base target
     base.cpu = "pentium".into();
     base.llvm_target = "i586-pc-windows-msvc".into();
     base
diff --git a/compiler/rustc_ty_utils/Cargo.toml b/compiler/rustc_ty_utils/Cargo.toml
index 40356e0c978..f88f8c38d50 100644
--- a/compiler/rustc_ty_utils/Cargo.toml
+++ b/compiler/rustc_ty_utils/Cargo.toml
@@ -11,6 +11,7 @@ rustc_ast_ir = { path = "../rustc_ast_ir" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
+rustc_hashes = { path = "../rustc_hashes" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_infer = { path = "../rustc_infer" }
diff --git a/compiler/rustc_ty_utils/src/layout.rs b/compiler/rustc_ty_utils/src/layout.rs
index ee271048fc1..8429e68b600 100644
--- a/compiler/rustc_ty_utils/src/layout.rs
+++ b/compiler/rustc_ty_utils/src/layout.rs
@@ -9,6 +9,7 @@ use rustc_abi::{
     HasDataLayout, Layout, LayoutCalculatorError, LayoutData, Niche, ReprOptions, Scalar, Size,
     StructKind, TagEncoding, VariantIdx, Variants, WrappingRange,
 };
+use rustc_hashes::Hash64;
 use rustc_index::bit_set::DenseBitSet;
 use rustc_index::{IndexSlice, IndexVec};
 use rustc_middle::bug;
@@ -380,7 +381,7 @@ fn layout_of_uncached<'tcx>(
                 size,
                 max_repr_align: None,
                 unadjusted_abi_align: element.align.abi,
-                randomization_seed: element.randomization_seed.wrapping_add(count),
+                randomization_seed: element.randomization_seed.wrapping_add(Hash64::new(count)),
             })
         }
         ty::Slice(element) => {
@@ -395,7 +396,9 @@ fn layout_of_uncached<'tcx>(
                 max_repr_align: None,
                 unadjusted_abi_align: element.align.abi,
                 // adding a randomly chosen value to distinguish slices
-                randomization_seed: element.randomization_seed.wrapping_add(0x2dcba99c39784102),
+                randomization_seed: element
+                    .randomization_seed
+                    .wrapping_add(Hash64::new(0x2dcba99c39784102)),
             })
         }
         ty::Str => tcx.mk_layout(LayoutData {
@@ -408,7 +411,7 @@ fn layout_of_uncached<'tcx>(
             max_repr_align: None,
             unadjusted_abi_align: dl.i8_align.abi,
             // another random value
-            randomization_seed: 0xc1325f37d127be22,
+            randomization_seed: Hash64::new(0xc1325f37d127be22),
         }),
 
         // Odd unit types.
@@ -585,7 +588,7 @@ fn layout_of_uncached<'tcx>(
                 align,
                 max_repr_align: None,
                 unadjusted_abi_align: align.abi,
-                randomization_seed: e_ly.randomization_seed.wrapping_add(e_len),
+                randomization_seed: e_ly.randomization_seed.wrapping_add(Hash64::new(e_len)),
             })
         }
 
@@ -1051,7 +1054,7 @@ fn coroutine_layout<'tcx>(
     };
 
     // this is similar to how ReprOptions populates its field_shuffle_seed
-    let def_hash = tcx.def_path_hash(def_id).0.to_smaller_hash().as_u64();
+    let def_hash = tcx.def_path_hash(def_id).0.to_smaller_hash();
 
     let layout = tcx.mk_layout(LayoutData {
         variants: Variants::Multiple {
diff --git a/compiler/rustc_type_ir/src/ty_kind.rs b/compiler/rustc_type_ir/src/ty_kind.rs
index 52e4fa19cb0..83631f7fe34 100644
--- a/compiler/rustc_type_ir/src/ty_kind.rs
+++ b/compiler/rustc_type_ir/src/ty_kind.rs
@@ -14,6 +14,7 @@ use rustc_type_ir_macros::{Lift_Generic, TypeFoldable_Generic, TypeVisitable_Gen
 use self::TyKind::*;
 pub use self::closure::*;
 use crate::inherent::*;
+#[cfg(feature = "nightly")]
 use crate::visit::TypeVisitable;
 use crate::{self as ty, DebruijnIndex, Interner};