diff --git a/compiler/rustc_abi/src/layout.rs b/compiler/rustc_abi/src/layout.rs
index e096ad7e6df..cea52c52785 100644
--- a/compiler/rustc_abi/src/layout.rs
+++ b/compiler/rustc_abi/src/layout.rs
@@ -1,14 +1,13 @@
-use super::*;
 use std::fmt::Write;
 use std::{borrow::Borrow, cmp, iter, ops::Bound};
 
-#[cfg(feature = "randomize")]
-use rand::{seq::SliceRandom, SeedableRng};
-#[cfg(feature = "randomize")]
-use rand_xoshiro::Xoshiro128StarStar;
-
 use tracing::debug;
 
+use crate::{
+    Abi, AbiAndPrefAlign, Align, FieldIdx, FieldsShape, IndexSlice, IndexVec, Integer, Layout,
+    LayoutS, Niche, NonZeroUsize, Primitive, ReprOptions, Scalar, Size, StructKind, TagEncoding,
+    TargetDataLayout, VariantIdx, Variants, WrappingRange, FIRST_VARIANT,
+};
 pub trait LayoutCalculator {
     type TargetDataLayoutRef: Borrow<TargetDataLayout>;
 
@@ -587,7 +586,7 @@ pub trait LayoutCalculator {
 
         let tag_mask = ity.size().unsigned_int_max();
         let tag = Scalar::Initialized {
-            value: Int(ity, signed),
+            value: Primitive::Int(ity, signed),
             valid_range: WrappingRange {
                 start: (min as u128 & tag_mask),
                 end: (max as u128 & tag_mask),
@@ -873,9 +872,12 @@ fn univariant(
         if repr.can_randomize_type_layout() && cfg!(feature = "randomize") {
             #[cfg(feature = "randomize")]
             {
+                use rand::{seq::SliceRandom, SeedableRng};
                 // `ReprOptions.layout_seed` is a deterministic seed we can use to randomize field
                 // ordering.
-                let mut rng = Xoshiro128StarStar::seed_from_u64(repr.field_shuffle_seed.as_u64());
+                let mut rng = rand_xoshiro::Xoshiro128StarStar::seed_from_u64(
+                    repr.field_shuffle_seed.as_u64(),
+                );
 
                 // Shuffle the ordering of the fields.
                 optimizing.shuffle(&mut rng);
diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs
index 31566c221cc..6a313936bf5 100644
--- a/compiler/rustc_abi/src/lib.rs
+++ b/compiler/rustc_abi/src/lib.rs
@@ -1,3 +1,5 @@
+// We want to be able to build this crate with a stable compiler, so no
+// `#![feature]` attributes should be added.
 #![cfg_attr(feature = "nightly", feature(step_trait, rustc_attrs, min_specialization))]
 #![cfg_attr(feature = "nightly", allow(internal_features))]
 
@@ -28,9 +30,6 @@ pub use layout::LayoutCalculator;
 /// instead of implementing everything in `rustc_middle`.
 pub trait HashStableContext {}
 
-use Integer::*;
-use Primitive::*;
-
 bitflags! {
     #[derive(Default)]
     #[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
@@ -342,6 +341,7 @@ impl TargetDataLayout {
 
     #[inline]
     pub fn ptr_sized_integer(&self) -> Integer {
+        use Integer::*;
         match self.pointer_size.bits() {
             16 => I16,
             32 => I32,
@@ -786,6 +786,7 @@ pub enum Integer {
 impl Integer {
     #[inline]
     pub fn size(self) -> Size {
+        use Integer::*;
         match self {
             I8 => Size::from_bytes(1),
             I16 => Size::from_bytes(2),
@@ -806,6 +807,7 @@ impl Integer {
     }
 
     pub fn align<C: HasDataLayout>(self, cx: &C) -> AbiAndPrefAlign {
+        use Integer::*;
         let dl = cx.data_layout();
 
         match self {
@@ -820,6 +822,7 @@ impl Integer {
     /// Returns the largest signed value that can be represented by this Integer.
     #[inline]
     pub fn signed_max(self) -> i128 {
+        use Integer::*;
         match self {
             I8 => i8::MAX as i128,
             I16 => i16::MAX as i128,
@@ -832,6 +835,7 @@ impl Integer {
     /// Finds the smallest Integer type which can represent the signed value.
     #[inline]
     pub fn fit_signed(x: i128) -> Integer {
+        use Integer::*;
         match x {
             -0x0000_0000_0000_0080..=0x0000_0000_0000_007f => I8,
             -0x0000_0000_0000_8000..=0x0000_0000_0000_7fff => I16,
@@ -844,6 +848,7 @@ impl Integer {
     /// Finds the smallest Integer type which can represent the unsigned value.
     #[inline]
     pub fn fit_unsigned(x: u128) -> Integer {
+        use Integer::*;
         match x {
             0..=0x0000_0000_0000_00ff => I8,
             0..=0x0000_0000_0000_ffff => I16,
@@ -855,6 +860,7 @@ impl Integer {
 
     /// Finds the smallest integer with the given alignment.
     pub fn for_align<C: HasDataLayout>(cx: &C, wanted: Align) -> Option<Integer> {
+        use Integer::*;
         let dl = cx.data_layout();
 
         [I8, I16, I32, I64, I128].into_iter().find(|&candidate| {
@@ -864,6 +870,7 @@ impl Integer {
 
     /// Find the largest integer with the given alignment or less.
     pub fn approximate_align<C: HasDataLayout>(cx: &C, wanted: Align) -> Integer {
+        use Integer::*;
         let dl = cx.data_layout();
 
         // FIXME(eddyb) maybe include I128 in the future, when it works everywhere.
@@ -909,6 +916,7 @@ pub enum Primitive {
 
 impl Primitive {
     pub fn size<C: HasDataLayout>(self, cx: &C) -> Size {
+        use Primitive::*;
         let dl = cx.data_layout();
 
         match self {
@@ -923,6 +931,7 @@ impl Primitive {
     }
 
     pub fn align<C: HasDataLayout>(self, cx: &C) -> AbiAndPrefAlign {
+        use Primitive::*;
         let dl = cx.data_layout();
 
         match self {
@@ -1027,10 +1036,11 @@ pub enum Scalar {
 impl Scalar {
     #[inline]
     pub fn is_bool(&self) -> bool {
+        use Integer::*;
         matches!(
             self,
             Scalar::Initialized {
-                value: Int(I8, false),
+                value: Primitive::Int(I8, false),
                 valid_range: WrappingRange { start: 0, end: 1 }
             }
         )