diff --git a/compiler/rustc_error_codes/src/error_codes/E0658.md b/compiler/rustc_error_codes/src/error_codes/E0658.md
index 24245a38ae07f..65c82e4fb6ef5 100644
--- a/compiler/rustc_error_codes/src/error_codes/E0658.md
+++ b/compiler/rustc_error_codes/src/error_codes/E0658.md
@@ -3,10 +3,7 @@ An unstable feature was used.
 Erroneous code example:
 
 ```compile_fail,E0658
-#[repr(u128)] // error: use of unstable library feature 'repr128'
-enum Foo {
-    Bar(u64),
-}
+use std::intrinsics; // error: use of unstable library feature `core_intrinsics`
 ```
 
 If you're using a stable or a beta version of rustc, you won't be able to use
@@ -17,12 +14,9 @@ If you're using a nightly version of rustc, just add the corresponding feature
 to be able to use it:
 
 ```
-#![feature(repr128)]
+#![feature(core_intrinsics)]
 
-#[repr(u128)] // ok!
-enum Foo {
-    Bar(u64),
-}
+use std::intrinsics; // ok!
 ```
 
 [rustup]: https://rust-lang.github.io/rustup/concepts/channels.html
diff --git a/compiler/rustc_feature/src/accepted.rs b/compiler/rustc_feature/src/accepted.rs
index d50fe8c6a3e6b..e8d46adea897c 100644
--- a/compiler/rustc_feature/src/accepted.rs
+++ b/compiler/rustc_feature/src/accepted.rs
@@ -350,6 +350,8 @@ declare_features! (
     (accepted, relaxed_adts, "1.19.0", Some(35626)),
     /// Lessens the requirements for structs to implement `Unsize`.
     (accepted, relaxed_struct_unsize, "1.58.0", Some(81793)),
+    /// Allows the `#[repr(i128)]` attribute for enums.
+    (accepted, repr128, "CURRENT_RUSTC_VERSION", Some(56071)),
     /// Allows `repr(align(16))` struct attribute (RFC 1358).
     (accepted, repr_align, "1.25.0", Some(33626)),
     /// Allows using `#[repr(align(X))]` on enums with equivalent semantics
diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
index 7741f6668c382..c2d98fe57b308 100644
--- a/compiler/rustc_feature/src/unstable.rs
+++ b/compiler/rustc_feature/src/unstable.rs
@@ -612,8 +612,6 @@ declare_features! (
     (incomplete, ref_pat_eat_one_layer_2024_structural, "1.81.0", Some(123076)),
     /// Allows using the `#[register_tool]` attribute.
     (unstable, register_tool, "1.41.0", Some(66079)),
-    /// Allows the `#[repr(i128)]` attribute for enums.
-    (incomplete, repr128, "1.16.0", Some(56071)),
     /// Allows `repr(simd)` and importing the various simd intrinsics.
     (unstable, repr_simd, "1.4.0", Some(27731)),
     /// Allows bounding the return type of AFIT/RPITIT.
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
index 8f9997cb62ca4..ffed18f0c7e97 100644
--- a/compiler/rustc_hir_analysis/src/check/check.rs
+++ b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -20,7 +20,7 @@ use rustc_middle::middle::stability::EvalResult;
 use rustc_middle::ty::error::TypeErrorToStringExt;
 use rustc_middle::ty::fold::{BottomUpFolder, fold_regions};
 use rustc_middle::ty::layout::{LayoutError, MAX_SIMD_LANES};
-use rustc_middle::ty::util::{Discr, IntTypeExt};
+use rustc_middle::ty::util::Discr;
 use rustc_middle::ty::{
     AdtDef, GenericArgKind, RegionKind, TypeSuperVisitable, TypeVisitable, TypeVisitableExt,
 };
@@ -1441,19 +1441,6 @@ fn check_enum(tcx: TyCtxt<'_>, def_id: LocalDefId) {
         );
     }
 
-    let repr_type_ty = def.repr().discr_type().to_ty(tcx);
-    if repr_type_ty == tcx.types.i128 || repr_type_ty == tcx.types.u128 {
-        if !tcx.features().repr128() {
-            feature_err(
-                &tcx.sess,
-                sym::repr128,
-                tcx.def_span(def_id),
-                "repr with 128-bit type is unstable",
-            )
-            .emit();
-        }
-    }
-
     for v in def.variants() {
         if let ty::VariantDiscr::Explicit(discr_def_id) = v.discr {
             tcx.ensure_ok().typeck(discr_def_id.expect_local());
diff --git a/src/doc/unstable-book/src/language-features/repr128.md b/src/doc/unstable-book/src/language-features/repr128.md
deleted file mode 100644
index 146f50ee67b50..0000000000000
--- a/src/doc/unstable-book/src/language-features/repr128.md
+++ /dev/null
@@ -1,18 +0,0 @@
-# `repr128`
-
-The tracking issue for this feature is: [#56071]
-
-[#56071]: https://github.com/rust-lang/rust/issues/56071
-
-------------------------
-
-The `repr128` feature adds support for `#[repr(u128)]` on `enum`s.
-
-```rust
-#![feature(repr128)]
-
-#[repr(u128)]
-enum Foo {
-    Bar(u64),
-}
-```
diff --git a/src/tools/clippy/tests/ui/auxiliary/proc_macro_attr.rs b/src/tools/clippy/tests/ui/auxiliary/proc_macro_attr.rs
index e72d6b6ceadfd..256d46a88bd01 100644
--- a/src/tools/clippy/tests/ui/auxiliary/proc_macro_attr.rs
+++ b/src/tools/clippy/tests/ui/auxiliary/proc_macro_attr.rs
@@ -1,5 +1,4 @@
-#![feature(repr128, proc_macro_hygiene, proc_macro_quote, box_patterns)]
-#![allow(incomplete_features)]
+#![feature(proc_macro_hygiene, proc_macro_quote, box_patterns)]
 #![allow(clippy::useless_conversion, clippy::uninlined_format_args)]
 
 extern crate proc_macro;
diff --git a/src/tools/clippy/tests/ui/auxiliary/proc_macro_derive.rs b/src/tools/clippy/tests/ui/auxiliary/proc_macro_derive.rs
index 1815dd58f5107..5992d15935d5b 100644
--- a/src/tools/clippy/tests/ui/auxiliary/proc_macro_derive.rs
+++ b/src/tools/clippy/tests/ui/auxiliary/proc_macro_derive.rs
@@ -1,5 +1,4 @@
-#![feature(repr128, proc_macro_quote, proc_macro_span)]
-#![allow(incomplete_features)]
+#![feature(proc_macro_quote, proc_macro_span)]
 #![allow(clippy::field_reassign_with_default)]
 #![allow(clippy::eq_op)]
 #![allow(clippy::literal_string_with_formatting_args)]
diff --git a/src/tools/clippy/tests/ui/cast.rs b/src/tools/clippy/tests/ui/cast.rs
index 88c2549f4dc50..36c2e7dab01ac 100644
--- a/src/tools/clippy/tests/ui/cast.rs
+++ b/src/tools/clippy/tests/ui/cast.rs
@@ -1,7 +1,5 @@
 //@no-rustfix
 
-#![feature(repr128)]
-#![allow(incomplete_features)]
 #![warn(
     clippy::cast_precision_loss,
     clippy::cast_possible_truncation,
diff --git a/src/tools/clippy/tests/ui/cast.stderr b/src/tools/clippy/tests/ui/cast.stderr
index 4d03282f6676e..1cb30d956679a 100644
--- a/src/tools/clippy/tests/ui/cast.stderr
+++ b/src/tools/clippy/tests/ui/cast.stderr
@@ -1,5 +1,5 @@
 error: casting `i32` to `f32` causes a loss of precision (`i32` is 32 bits wide, but `f32`'s mantissa is only 23 bits wide)
-  --> tests/ui/cast.rs:25:5
+  --> tests/ui/cast.rs:23:5
    |
 LL |     x0 as f32;
    |     ^^^^^^^^^
@@ -8,37 +8,37 @@ LL |     x0 as f32;
    = help: to override `-D warnings` add `#[allow(clippy::cast_precision_loss)]`
 
 error: casting `i64` to `f32` causes a loss of precision (`i64` is 64 bits wide, but `f32`'s mantissa is only 23 bits wide)
-  --> tests/ui/cast.rs:29:5
+  --> tests/ui/cast.rs:27:5
    |
 LL |     x1 as f32;
    |     ^^^^^^^^^
 
 error: casting `i64` to `f64` causes a loss of precision (`i64` is 64 bits wide, but `f64`'s mantissa is only 52 bits wide)
-  --> tests/ui/cast.rs:32:5
+  --> tests/ui/cast.rs:30:5
    |
 LL |     x1 as f64;
    |     ^^^^^^^^^
 
 error: casting `u32` to `f32` causes a loss of precision (`u32` is 32 bits wide, but `f32`'s mantissa is only 23 bits wide)
-  --> tests/ui/cast.rs:36:5
+  --> tests/ui/cast.rs:34:5
    |
 LL |     x2 as f32;
    |     ^^^^^^^^^
 
 error: casting `u64` to `f32` causes a loss of precision (`u64` is 64 bits wide, but `f32`'s mantissa is only 23 bits wide)
-  --> tests/ui/cast.rs:40:5
+  --> tests/ui/cast.rs:38:5
    |
 LL |     x3 as f32;
    |     ^^^^^^^^^
 
 error: casting `u64` to `f64` causes a loss of precision (`u64` is 64 bits wide, but `f64`'s mantissa is only 52 bits wide)
-  --> tests/ui/cast.rs:43:5
+  --> tests/ui/cast.rs:41:5
    |
 LL |     x3 as f64;
    |     ^^^^^^^^^
 
 error: casting `f32` to `i32` may truncate the value
-  --> tests/ui/cast.rs:47:5
+  --> tests/ui/cast.rs:45:5
    |
 LL |     1f32 as i32;
    |     ^^^^^^^^^^^
@@ -48,7 +48,7 @@ LL |     1f32 as i32;
    = help: to override `-D warnings` add `#[allow(clippy::cast_possible_truncation)]`
 
 error: casting `f32` to `u32` may truncate the value
-  --> tests/ui/cast.rs:50:5
+  --> tests/ui/cast.rs:48:5
    |
 LL |     1f32 as u32;
    |     ^^^^^^^^^^^
@@ -56,7 +56,7 @@ LL |     1f32 as u32;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:50:5
+  --> tests/ui/cast.rs:48:5
    |
 LL |     1f32 as u32;
    |     ^^^^^^^^^^^
@@ -65,7 +65,7 @@ LL |     1f32 as u32;
    = help: to override `-D warnings` add `#[allow(clippy::cast_sign_loss)]`
 
 error: casting `f64` to `f32` may truncate the value
-  --> tests/ui/cast.rs:54:5
+  --> tests/ui/cast.rs:52:5
    |
 LL |     1f64 as f32;
    |     ^^^^^^^^^^^
@@ -73,7 +73,7 @@ LL |     1f64 as f32;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `i32` to `i8` may truncate the value
-  --> tests/ui/cast.rs:57:5
+  --> tests/ui/cast.rs:55:5
    |
 LL |     1i32 as i8;
    |     ^^^^^^^^^^
@@ -86,7 +86,7 @@ LL +     i8::try_from(1i32);
    |
 
 error: casting `i32` to `u8` may truncate the value
-  --> tests/ui/cast.rs:60:5
+  --> tests/ui/cast.rs:58:5
    |
 LL |     1i32 as u8;
    |     ^^^^^^^^^^
@@ -99,7 +99,7 @@ LL +     u8::try_from(1i32);
    |
 
 error: casting `f64` to `isize` may truncate the value
-  --> tests/ui/cast.rs:63:5
+  --> tests/ui/cast.rs:61:5
    |
 LL |     1f64 as isize;
    |     ^^^^^^^^^^^^^
@@ -107,7 +107,7 @@ LL |     1f64 as isize;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f64` to `usize` may truncate the value
-  --> tests/ui/cast.rs:66:5
+  --> tests/ui/cast.rs:64:5
    |
 LL |     1f64 as usize;
    |     ^^^^^^^^^^^^^
@@ -115,13 +115,13 @@ LL |     1f64 as usize;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f64` to `usize` may lose the sign of the value
-  --> tests/ui/cast.rs:66:5
+  --> tests/ui/cast.rs:64:5
    |
 LL |     1f64 as usize;
    |     ^^^^^^^^^^^^^
 
 error: casting `u32` to `u16` may truncate the value
-  --> tests/ui/cast.rs:70:5
+  --> tests/ui/cast.rs:68:5
    |
 LL |     1f32 as u32 as u16;
    |     ^^^^^^^^^^^^^^^^^^
@@ -134,7 +134,7 @@ LL +     u16::try_from(1f32 as u32);
    |
 
 error: casting `f32` to `u32` may truncate the value
-  --> tests/ui/cast.rs:70:5
+  --> tests/ui/cast.rs:68:5
    |
 LL |     1f32 as u32 as u16;
    |     ^^^^^^^^^^^
@@ -142,13 +142,13 @@ LL |     1f32 as u32 as u16;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:70:5
+  --> tests/ui/cast.rs:68:5
    |
 LL |     1f32 as u32 as u16;
    |     ^^^^^^^^^^^
 
 error: casting `i32` to `i8` may truncate the value
-  --> tests/ui/cast.rs:76:22
+  --> tests/ui/cast.rs:74:22
    |
 LL |         let _x: i8 = 1i32 as _;
    |                      ^^^^^^^^^
@@ -161,7 +161,7 @@ LL +         let _x: i8 = 1i32.try_into();
    |
 
 error: casting `f32` to `i32` may truncate the value
-  --> tests/ui/cast.rs:79:9
+  --> tests/ui/cast.rs:77:9
    |
 LL |         1f32 as i32;
    |         ^^^^^^^^^^^
@@ -169,7 +169,7 @@ LL |         1f32 as i32;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f64` to `i32` may truncate the value
-  --> tests/ui/cast.rs:82:9
+  --> tests/ui/cast.rs:80:9
    |
 LL |         1f64 as i32;
    |         ^^^^^^^^^^^
@@ -177,7 +177,7 @@ LL |         1f64 as i32;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f32` to `u8` may truncate the value
-  --> tests/ui/cast.rs:85:9
+  --> tests/ui/cast.rs:83:9
    |
 LL |         1f32 as u8;
    |         ^^^^^^^^^^
@@ -185,13 +185,13 @@ LL |         1f32 as u8;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f32` to `u8` may lose the sign of the value
-  --> tests/ui/cast.rs:85:9
+  --> tests/ui/cast.rs:83:9
    |
 LL |         1f32 as u8;
    |         ^^^^^^^^^^
 
 error: casting `u8` to `i8` may wrap around the value
-  --> tests/ui/cast.rs:90:5
+  --> tests/ui/cast.rs:88:5
    |
 LL |     1u8 as i8;
    |     ^^^^^^^^^
@@ -200,31 +200,31 @@ LL |     1u8 as i8;
    = help: to override `-D warnings` add `#[allow(clippy::cast_possible_wrap)]`
 
 error: casting `u16` to `i16` may wrap around the value
-  --> tests/ui/cast.rs:93:5
+  --> tests/ui/cast.rs:91:5
    |
 LL |     1u16 as i16;
    |     ^^^^^^^^^^^
 
 error: casting `u32` to `i32` may wrap around the value
-  --> tests/ui/cast.rs:96:5
+  --> tests/ui/cast.rs:94:5
    |
 LL |     1u32 as i32;
    |     ^^^^^^^^^^^
 
 error: casting `u64` to `i64` may wrap around the value
-  --> tests/ui/cast.rs:99:5
+  --> tests/ui/cast.rs:97:5
    |
 LL |     1u64 as i64;
    |     ^^^^^^^^^^^
 
 error: casting `usize` to `isize` may wrap around the value
-  --> tests/ui/cast.rs:102:5
+  --> tests/ui/cast.rs:100:5
    |
 LL |     1usize as isize;
    |     ^^^^^^^^^^^^^^^
 
 error: casting `usize` to `i8` may truncate the value
-  --> tests/ui/cast.rs:106:5
+  --> tests/ui/cast.rs:104:5
    |
 LL |     1usize as i8;
    |     ^^^^^^^^^^^^
@@ -237,7 +237,7 @@ LL +     i8::try_from(1usize);
    |
 
 error: casting `usize` to `i16` may truncate the value
-  --> tests/ui/cast.rs:110:5
+  --> tests/ui/cast.rs:108:5
    |
 LL |     1usize as i16;
    |     ^^^^^^^^^^^^^
@@ -250,7 +250,7 @@ LL +     i16::try_from(1usize);
    |
 
 error: casting `usize` to `i16` may wrap around the value on targets with 16-bit wide pointers
-  --> tests/ui/cast.rs:110:5
+  --> tests/ui/cast.rs:108:5
    |
 LL |     1usize as i16;
    |     ^^^^^^^^^^^^^
@@ -259,7 +259,7 @@ LL |     1usize as i16;
    = note: for more information see https://doc.rust-lang.org/reference/types/numeric.html#machine-dependent-integer-types
 
 error: casting `usize` to `i32` may truncate the value on targets with 64-bit wide pointers
-  --> tests/ui/cast.rs:115:5
+  --> tests/ui/cast.rs:113:5
    |
 LL |     1usize as i32;
    |     ^^^^^^^^^^^^^
@@ -272,19 +272,19 @@ LL +     i32::try_from(1usize);
    |
 
 error: casting `usize` to `i32` may wrap around the value on targets with 32-bit wide pointers
-  --> tests/ui/cast.rs:115:5
+  --> tests/ui/cast.rs:113:5
    |
 LL |     1usize as i32;
    |     ^^^^^^^^^^^^^
 
 error: casting `usize` to `i64` may wrap around the value on targets with 64-bit wide pointers
-  --> tests/ui/cast.rs:120:5
+  --> tests/ui/cast.rs:118:5
    |
 LL |     1usize as i64;
    |     ^^^^^^^^^^^^^
 
 error: casting `u16` to `isize` may wrap around the value on targets with 16-bit wide pointers
-  --> tests/ui/cast.rs:126:5
+  --> tests/ui/cast.rs:124:5
    |
 LL |     1u16 as isize;
    |     ^^^^^^^^^^^^^
@@ -293,13 +293,13 @@ LL |     1u16 as isize;
    = note: for more information see https://doc.rust-lang.org/reference/types/numeric.html#machine-dependent-integer-types
 
 error: casting `u32` to `isize` may wrap around the value on targets with 32-bit wide pointers
-  --> tests/ui/cast.rs:130:5
+  --> tests/ui/cast.rs:128:5
    |
 LL |     1u32 as isize;
    |     ^^^^^^^^^^^^^
 
 error: casting `u64` to `isize` may truncate the value on targets with 32-bit wide pointers
-  --> tests/ui/cast.rs:134:5
+  --> tests/ui/cast.rs:132:5
    |
 LL |     1u64 as isize;
    |     ^^^^^^^^^^^^^
@@ -312,55 +312,55 @@ LL +     isize::try_from(1u64);
    |
 
 error: casting `u64` to `isize` may wrap around the value on targets with 64-bit wide pointers
-  --> tests/ui/cast.rs:134:5
+  --> tests/ui/cast.rs:132:5
    |
 LL |     1u64 as isize;
    |     ^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:140:5
+  --> tests/ui/cast.rs:138:5
    |
 LL |     -1i32 as u32;
    |     ^^^^^^^^^^^^
 
 error: casting `isize` to `usize` may lose the sign of the value
-  --> tests/ui/cast.rs:144:5
+  --> tests/ui/cast.rs:142:5
    |
 LL |     -1isize as usize;
    |     ^^^^^^^^^^^^^^^^
 
 error: casting `i8` to `u8` may lose the sign of the value
-  --> tests/ui/cast.rs:156:5
+  --> tests/ui/cast.rs:154:5
    |
 LL |     (i8::MIN).abs() as u8;
    |     ^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i64` to `u64` may lose the sign of the value
-  --> tests/ui/cast.rs:161:5
+  --> tests/ui/cast.rs:159:5
    |
 LL |     (-1i64).abs() as u64;
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: casting `isize` to `usize` may lose the sign of the value
-  --> tests/ui/cast.rs:163:5
+  --> tests/ui/cast.rs:161:5
    |
 LL |     (-1isize).abs() as usize;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i64` to `u64` may lose the sign of the value
-  --> tests/ui/cast.rs:171:5
+  --> tests/ui/cast.rs:169:5
    |
 LL |     (unsafe { (-1i64).checked_abs().unwrap_unchecked() }) as u64;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i64` to `u64` may lose the sign of the value
-  --> tests/ui/cast.rs:187:5
+  --> tests/ui/cast.rs:185:5
    |
 LL |     (unsafe { (-1i64).checked_isqrt().unwrap_unchecked() }) as u64;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i64` to `i8` may truncate the value
-  --> tests/ui/cast.rs:239:5
+  --> tests/ui/cast.rs:237:5
    |
 LL |     (-99999999999i64).min(1) as i8;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -373,7 +373,7 @@ LL +     i8::try_from((-99999999999i64).min(1));
    |
 
 error: casting `u64` to `u8` may truncate the value
-  --> tests/ui/cast.rs:253:5
+  --> tests/ui/cast.rs:251:5
    |
 LL |     999999u64.clamp(0, 256) as u8;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -386,7 +386,7 @@ LL +     u8::try_from(999999u64.clamp(0, 256));
    |
 
 error: casting `main::E2` to `u8` may truncate the value
-  --> tests/ui/cast.rs:276:21
+  --> tests/ui/cast.rs:274:21
    |
 LL |             let _ = self as u8;
    |                     ^^^^^^^^^^
@@ -399,7 +399,7 @@ LL +             let _ = u8::try_from(self);
    |
 
 error: casting `main::E2::B` to `u8` will truncate the value
-  --> tests/ui/cast.rs:279:21
+  --> tests/ui/cast.rs:277:21
    |
 LL |             let _ = Self::B as u8;
    |                     ^^^^^^^^^^^^^
@@ -408,7 +408,7 @@ LL |             let _ = Self::B as u8;
    = help: to override `-D warnings` add `#[allow(clippy::cast_enum_truncation)]`
 
 error: casting `main::E5` to `i8` may truncate the value
-  --> tests/ui/cast.rs:321:21
+  --> tests/ui/cast.rs:319:21
    |
 LL |             let _ = self as i8;
    |                     ^^^^^^^^^^
@@ -421,13 +421,13 @@ LL +             let _ = i8::try_from(self);
    |
 
 error: casting `main::E5::A` to `i8` will truncate the value
-  --> tests/ui/cast.rs:324:21
+  --> tests/ui/cast.rs:322:21
    |
 LL |             let _ = Self::A as i8;
    |                     ^^^^^^^^^^^^^
 
 error: casting `main::E6` to `i16` may truncate the value
-  --> tests/ui/cast.rs:342:21
+  --> tests/ui/cast.rs:340:21
    |
 LL |             let _ = self as i16;
    |                     ^^^^^^^^^^^
@@ -440,7 +440,7 @@ LL +             let _ = i16::try_from(self);
    |
 
 error: casting `main::E7` to `usize` may truncate the value on targets with 32-bit wide pointers
-  --> tests/ui/cast.rs:362:21
+  --> tests/ui/cast.rs:360:21
    |
 LL |             let _ = self as usize;
    |                     ^^^^^^^^^^^^^
@@ -453,7 +453,7 @@ LL +             let _ = usize::try_from(self);
    |
 
 error: casting `main::E10` to `u16` may truncate the value
-  --> tests/ui/cast.rs:410:21
+  --> tests/ui/cast.rs:408:21
    |
 LL |             let _ = self as u16;
    |                     ^^^^^^^^^^^
@@ -466,7 +466,7 @@ LL +             let _ = u16::try_from(self);
    |
 
 error: casting `u32` to `u8` may truncate the value
-  --> tests/ui/cast.rs:422:13
+  --> tests/ui/cast.rs:420:13
    |
 LL |     let c = (q >> 16) as u8;
    |             ^^^^^^^^^^^^^^^
@@ -479,7 +479,7 @@ LL +     let c = u8::try_from(q >> 16);
    |
 
 error: casting `u32` to `u8` may truncate the value
-  --> tests/ui/cast.rs:427:13
+  --> tests/ui/cast.rs:425:13
    |
 LL |     let c = (q / 1000) as u8;
    |             ^^^^^^^^^^^^^^^^
@@ -492,85 +492,85 @@ LL +     let c = u8::try_from(q / 1000);
    |
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:440:9
+  --> tests/ui/cast.rs:438:9
    |
 LL |         (x * x) as u32;
    |         ^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:446:32
+  --> tests/ui/cast.rs:444:32
    |
 LL |     let _a = |x: i32| -> u32 { (x * x * x * x) as u32 };
    |                                ^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:449:5
+  --> tests/ui/cast.rs:447:5
    |
 LL |     (2_i32).checked_pow(3).unwrap() as u32;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:451:5
+  --> tests/ui/cast.rs:449:5
    |
 LL |     (-2_i32).pow(3) as u32;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:456:5
+  --> tests/ui/cast.rs:454:5
    |
 LL |     (-5_i32 % 2) as u32;
    |     ^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:459:5
+  --> tests/ui/cast.rs:457:5
    |
 LL |     (-5_i32 % -2) as u32;
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:463:5
+  --> tests/ui/cast.rs:461:5
    |
 LL |     (-2_i32 >> 1) as u32;
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:467:5
+  --> tests/ui/cast.rs:465:5
    |
 LL |     (x * x) as u32;
    |     ^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:469:5
+  --> tests/ui/cast.rs:467:5
    |
 LL |     (x * x * x) as u32;
    |     ^^^^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:473:5
+  --> tests/ui/cast.rs:471:5
    |
 LL |     (y * y * y * y * -2) as u16;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:476:5
+  --> tests/ui/cast.rs:474:5
    |
 LL |     (y * y * y / y * 2) as u16;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:478:5
+  --> tests/ui/cast.rs:476:5
    |
 LL |     (y * y / y * 2) as u16;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:481:5
+  --> tests/ui/cast.rs:479:5
    |
 LL |     (y / y * y * -2) as u16;
    |     ^^^^^^^^^^^^^^^^^^^^^^^
 
 error: equal expressions as operands to `/`
-  --> tests/ui/cast.rs:481:6
+  --> tests/ui/cast.rs:479:6
    |
 LL |     (y / y * y * -2) as u16;
    |      ^^^^^
@@ -578,97 +578,97 @@ LL |     (y / y * y * -2) as u16;
    = note: `#[deny(clippy::eq_op)]` on by default
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:485:5
+  --> tests/ui/cast.rs:483:5
    |
 LL |     (y + y + y + -2) as u16;
    |     ^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:488:5
+  --> tests/ui/cast.rs:486:5
    |
 LL |     (y + y + y + 2) as u16;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:492:5
+  --> tests/ui/cast.rs:490:5
    |
 LL |     (z + -2) as u16;
    |     ^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:495:5
+  --> tests/ui/cast.rs:493:5
    |
 LL |     (z + z + 2) as u16;
    |     ^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:499:9
+  --> tests/ui/cast.rs:497:9
    |
 LL |         (a * a * b * b * c * c) as u32;
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:501:9
+  --> tests/ui/cast.rs:499:9
    |
 LL |         (a * b * c) as u32;
    |         ^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:504:9
+  --> tests/ui/cast.rs:502:9
    |
 LL |         (a * -b * c) as u32;
    |         ^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:507:9
+  --> tests/ui/cast.rs:505:9
    |
 LL |         (a * b * c * c) as u32;
    |         ^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:509:9
+  --> tests/ui/cast.rs:507:9
    |
 LL |         (a * -2) as u32;
    |         ^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:512:9
+  --> tests/ui/cast.rs:510:9
    |
 LL |         (a * b * c * -2) as u32;
    |         ^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:515:9
+  --> tests/ui/cast.rs:513:9
    |
 LL |         (a / b) as u32;
    |         ^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:517:9
+  --> tests/ui/cast.rs:515:9
    |
 LL |         (a / b * c) as u32;
    |         ^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:520:9
+  --> tests/ui/cast.rs:518:9
    |
 LL |         (a / b + b * c) as u32;
    |         ^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:523:9
+  --> tests/ui/cast.rs:521:9
    |
 LL |         a.saturating_pow(3) as u32;
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:526:9
+  --> tests/ui/cast.rs:524:9
    |
 LL |         (a.abs() * b.pow(2) / c.abs()) as u32
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:534:21
+  --> tests/ui/cast.rs:532:21
    |
 LL |             let _ = i32::MIN as u32; // cast_sign_loss
    |                     ^^^^^^^^^^^^^^^
@@ -679,7 +679,7 @@ LL |     m!();
    = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: casting `u32` to `u8` may truncate the value
-  --> tests/ui/cast.rs:537:21
+  --> tests/ui/cast.rs:535:21
    |
 LL |             let _ = u32::MAX as u8; // cast_possible_truncation
    |                     ^^^^^^^^^^^^^^
@@ -696,7 +696,7 @@ LL +             let _ = u8::try_from(u32::MAX); // cast_possible_truncation
    |
 
 error: casting `f64` to `f32` may truncate the value
-  --> tests/ui/cast.rs:540:21
+  --> tests/ui/cast.rs:538:21
    |
 LL |             let _ = std::f64::consts::PI as f32; // cast_possible_truncation
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -708,7 +708,7 @@ LL |     m!();
    = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: casting `i64` to `usize` may truncate the value on targets with 32-bit wide pointers
-  --> tests/ui/cast.rs:551:5
+  --> tests/ui/cast.rs:549:5
    |
 LL |     bar.unwrap().unwrap() as usize
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -721,13 +721,13 @@ LL +     usize::try_from(bar.unwrap().unwrap())
    |
 
 error: casting `i64` to `usize` may lose the sign of the value
-  --> tests/ui/cast.rs:551:5
+  --> tests/ui/cast.rs:549:5
    |
 LL |     bar.unwrap().unwrap() as usize
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `u64` to `u8` may truncate the value
-  --> tests/ui/cast.rs:568:5
+  --> tests/ui/cast.rs:566:5
    |
 LL |     (256 & 999999u64) as u8;
    |     ^^^^^^^^^^^^^^^^^^^^^^^
@@ -740,7 +740,7 @@ LL +     u8::try_from(256 & 999999u64);
    |
 
 error: casting `u64` to `u8` may truncate the value
-  --> tests/ui/cast.rs:571:5
+  --> tests/ui/cast.rs:569:5
    |
 LL |     (255 % 999999u64) as u8;
    |     ^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/src/tools/clippy/tests/ui/crashes/auxiliary/proc_macro_crash.rs b/src/tools/clippy/tests/ui/crashes/auxiliary/proc_macro_crash.rs
index 5dffddc119aa3..cf37a4c5c4bb3 100644
--- a/src/tools/clippy/tests/ui/crashes/auxiliary/proc_macro_crash.rs
+++ b/src/tools/clippy/tests/ui/crashes/auxiliary/proc_macro_crash.rs
@@ -1,6 +1,3 @@
-#![feature(repr128)]
-#![allow(incomplete_features)]
-
 extern crate proc_macro;
 
 use proc_macro::{Delimiter, Group, Ident, Span, TokenStream, TokenTree};
diff --git a/src/tools/tidy/src/issues.txt b/src/tools/tidy/src/issues.txt
index 253e13375c73c..72f4e410d4f96 100644
--- a/src/tools/tidy/src/issues.txt
+++ b/src/tools/tidy/src/issues.txt
@@ -945,7 +945,6 @@ ui/enum-discriminant/auxiliary/issue-41394.rs
 ui/enum-discriminant/issue-104519.rs
 ui/enum-discriminant/issue-41394-rpass.rs
 ui/enum-discriminant/issue-41394.rs
-ui/enum-discriminant/issue-43398.rs
 ui/enum-discriminant/issue-46519.rs
 ui/enum-discriminant/issue-50689.rs
 ui/enum-discriminant/issue-51582.rs
diff --git a/tests/codegen/enum/enum-u128.rs b/tests/codegen/enum/enum-u128.rs
index ecdff3c5ce31d..2676669f3e308 100644
--- a/tests/codegen/enum/enum-u128.rs
+++ b/tests/codegen/enum/enum-u128.rs
@@ -13,9 +13,6 @@
 // CHECK: {{.*}}DIEnumerator{{.*}}name: "Hi",{{.*}}value: 18446744073709551616,{{.*}}
 // CHECK: {{.*}}DIEnumerator{{.*}}name: "Bar",{{.*}}value: 18446745000000000123,{{.*}}
 
-#![allow(incomplete_features)]
-#![feature(repr128)]
-
 #[repr(u128)]
 pub enum Foo {
     Lo,
diff --git a/tests/debuginfo/msvc-pretty-enums.rs b/tests/debuginfo/msvc-pretty-enums.rs
index 06bc25dc5d59c..aa6629ef1e1be 100644
--- a/tests/debuginfo/msvc-pretty-enums.rs
+++ b/tests/debuginfo/msvc-pretty-enums.rs
@@ -231,8 +231,6 @@
 // cdb-command: dx c_style_i128_d
 // cdb-check: c_style_i128_d   : D [Type: enum2$<msvc_pretty_enums::CStyleI128>]
 #![feature(rustc_attrs)]
-#![feature(repr128)]
-#![feature(arbitrary_enum_discriminant)]
 
 use std::num::NonZero;
 
diff --git a/tests/mir-opt/enum_opt.rs b/tests/mir-opt/enum_opt.rs
index e42be8ac06dc9..81390567c2bb4 100644
--- a/tests/mir-opt/enum_opt.rs
+++ b/tests/mir-opt/enum_opt.rs
@@ -3,8 +3,6 @@
 // EMIT_MIR_FOR_EACH_BIT_WIDTH
 //@ compile-flags: -Zunsound-mir-opts -Zdump-mir-exclude-alloc-bytes
 
-#![feature(arbitrary_enum_discriminant, repr128)]
-
 // Tests that an enum with a variant with no data gets correctly transformed.
 pub enum NoData {
     Large([u8; 8196]),
diff --git a/tests/mir-opt/matches_reduce_branches.rs b/tests/mir-opt/matches_reduce_branches.rs
index 3372ae2f2a614..00131b0116db0 100644
--- a/tests/mir-opt/matches_reduce_branches.rs
+++ b/tests/mir-opt/matches_reduce_branches.rs
@@ -1,6 +1,5 @@
 //@ test-mir-pass: MatchBranchSimplification
 
-#![feature(repr128)]
 #![feature(core_intrinsics)]
 #![feature(custom_mir)]
 #![allow(non_camel_case_types)]
diff --git a/tests/run-make/repr128-dwarf/main.rs b/tests/run-make/repr128-dwarf/main.rs
index 9842ab4a3426f..a8a414fd72e40 100644
--- a/tests/run-make/repr128-dwarf/main.rs
+++ b/tests/run-make/repr128-dwarf/main.rs
@@ -1,5 +1,3 @@
-#![feature(repr128)]
-
 // Use .to_le() to ensure that the bytes are in the same order on both little- and big-endian
 // platforms.
 
diff --git a/tests/rustdoc-json/enums/discriminant/limits.rs b/tests/rustdoc-json/enums/discriminant/limits.rs
index 7508490d6661e..7939cee4855a6 100644
--- a/tests/rustdoc-json/enums/discriminant/limits.rs
+++ b/tests/rustdoc-json/enums/discriminant/limits.rs
@@ -1,6 +1,3 @@
-#![feature(repr128)]
-#![allow(incomplete_features)]
-
 #[repr(u64)]
 pub enum U64 {
     //@ is "$.index[*][?(@.name=='U64Min')].inner.variant.discriminant.value" '"0"'
diff --git a/tests/ui/enum-discriminant/discriminant_size.rs b/tests/ui/enum-discriminant/discriminant_size.rs
index a3ec1b28e5c76..b1feff3c59e1d 100644
--- a/tests/ui/enum-discriminant/discriminant_size.rs
+++ b/tests/ui/enum-discriminant/discriminant_size.rs
@@ -1,6 +1,5 @@
 //@ run-pass
-#![feature(core_intrinsics, repr128)]
-//~^ WARN the feature `repr128` is incomplete
+#![feature(core_intrinsics)]
 
 use std::intrinsics::discriminant_value;
 
diff --git a/tests/ui/enum-discriminant/discriminant_size.stderr b/tests/ui/enum-discriminant/discriminant_size.stderr
deleted file mode 100644
index 9b1505b5c468d..0000000000000
--- a/tests/ui/enum-discriminant/discriminant_size.stderr
+++ /dev/null
@@ -1,11 +0,0 @@
-warning: the feature `repr128` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/discriminant_size.rs:2:29
-   |
-LL | #![feature(core_intrinsics, repr128)]
-   |                             ^^^^^^^
-   |
-   = note: see issue #56071 <https://github.com/rust-lang/rust/issues/56071> for more information
-   = note: `#[warn(incomplete_features)]` on by default
-
-warning: 1 warning emitted
-
diff --git a/tests/ui/enum-discriminant/issue-43398.stderr b/tests/ui/enum-discriminant/issue-43398.stderr
deleted file mode 100644
index fc7bbd0628434..0000000000000
--- a/tests/ui/enum-discriminant/issue-43398.stderr
+++ /dev/null
@@ -1,11 +0,0 @@
-warning: the feature `repr128` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/issue-43398.rs:4:12
-   |
-LL | #![feature(repr128)]
-   |            ^^^^^^^
-   |
-   = note: see issue #56071 <https://github.com/rust-lang/rust/issues/56071> for more information
-   = note: `#[warn(incomplete_features)]` on by default
-
-warning: 1 warning emitted
-
diff --git a/tests/ui/enum-discriminant/issue-70509-partial_eq.rs b/tests/ui/enum-discriminant/issue-70509-partial_eq.rs
index e98532c120793..5e71972c28086 100644
--- a/tests/ui/enum-discriminant/issue-70509-partial_eq.rs
+++ b/tests/ui/enum-discriminant/issue-70509-partial_eq.rs
@@ -1,6 +1,4 @@
 //@ run-pass
-#![feature(repr128)]
-//~^ WARN the feature `repr128` is incomplete
 
 #[derive(PartialEq, Debug)]
 #[repr(i128)]
diff --git a/tests/ui/enum-discriminant/issue-70509-partial_eq.stderr b/tests/ui/enum-discriminant/issue-70509-partial_eq.stderr
deleted file mode 100644
index 2eef930c39434..0000000000000
--- a/tests/ui/enum-discriminant/issue-70509-partial_eq.stderr
+++ /dev/null
@@ -1,11 +0,0 @@
-warning: the feature `repr128` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/issue-70509-partial_eq.rs:2:12
-   |
-LL | #![feature(repr128)]
-   |            ^^^^^^^
-   |
-   = note: see issue #56071 <https://github.com/rust-lang/rust/issues/56071> for more information
-   = note: `#[warn(incomplete_features)]` on by default
-
-warning: 1 warning emitted
-
diff --git a/tests/ui/enum-discriminant/issue-43398.rs b/tests/ui/enum-discriminant/repr128-get-discriminant-issue-43398.rs
similarity index 75%
rename from tests/ui/enum-discriminant/issue-43398.rs
rename to tests/ui/enum-discriminant/repr128-get-discriminant-issue-43398.rs
index 574a4b3ad5a09..2bb9725fb77d1 100644
--- a/tests/ui/enum-discriminant/issue-43398.rs
+++ b/tests/ui/enum-discriminant/repr128-get-discriminant-issue-43398.rs
@@ -1,8 +1,6 @@
 //@ run-pass
 
 #![feature(core_intrinsics)]
-#![feature(repr128)]
-//~^ WARN the feature `repr128` is incomplete
 
 #[repr(i128)]
 enum Big { A, B }
diff --git a/tests/ui/enum-discriminant/repr128.rs b/tests/ui/enum-discriminant/repr128.rs
index 075ff7a767613..d59a5b3e256d2 100644
--- a/tests/ui/enum-discriminant/repr128.rs
+++ b/tests/ui/enum-discriminant/repr128.rs
@@ -1,6 +1,5 @@
 //@ run-pass
-#![feature(repr128, core_intrinsics, discriminant_kind)]
-//~^ WARN the feature `repr128` is incomplete
+#![feature(core_intrinsics, discriminant_kind)]
 
 use std::intrinsics::discriminant_value;
 use std::marker::DiscriminantKind;
diff --git a/tests/ui/enum-discriminant/repr128.stderr b/tests/ui/enum-discriminant/repr128.stderr
deleted file mode 100644
index da8d75c11aff2..0000000000000
--- a/tests/ui/enum-discriminant/repr128.stderr
+++ /dev/null
@@ -1,11 +0,0 @@
-warning: the feature `repr128` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/repr128.rs:2:12
-   |
-LL | #![feature(repr128, core_intrinsics, discriminant_kind)]
-   |            ^^^^^^^
-   |
-   = note: see issue #56071 <https://github.com/rust-lang/rust/issues/56071> for more information
-   = note: `#[warn(incomplete_features)]` on by default
-
-warning: 1 warning emitted
-
diff --git a/tests/ui/error-codes/E0658.rs b/tests/ui/error-codes/E0658.rs
index 9c9b95d70a7cf..e51674cdf92ed 100644
--- a/tests/ui/error-codes/E0658.rs
+++ b/tests/ui/error-codes/E0658.rs
@@ -1,6 +1,3 @@
-#[repr(u128)]
-enum Foo { //~ ERROR E0658
-    Bar(u64),
-}
+use std::intrinsics; //~ ERROR E0658
 
 fn main() {}
diff --git a/tests/ui/error-codes/E0658.stderr b/tests/ui/error-codes/E0658.stderr
index e1e812940ec54..ae7ecbbc5cb0a 100644
--- a/tests/ui/error-codes/E0658.stderr
+++ b/tests/ui/error-codes/E0658.stderr
@@ -1,11 +1,10 @@
-error[E0658]: repr with 128-bit type is unstable
-  --> $DIR/E0658.rs:2:1
+error[E0658]: use of unstable library feature `core_intrinsics`: intrinsics are unlikely to ever be stabilized, instead they should be used through stabilized interfaces in the rest of the standard library
+  --> $DIR/E0658.rs:1:5
    |
-LL | enum Foo {
-   | ^^^^^^^^
+LL | use std::intrinsics;
+   |     ^^^^^^^^^^^^^^^
    |
-   = note: see issue #56071 <https://github.com/rust-lang/rust/issues/56071> for more information
-   = help: add `#![feature(repr128)]` to the crate attributes to enable
+   = help: add `#![feature(core_intrinsics)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error: aborting due to 1 previous error
diff --git a/tests/ui/feature-gates/feature-gate-repr128.rs b/tests/ui/feature-gates/feature-gate-repr128.rs
deleted file mode 100644
index 0290874dd27f8..0000000000000
--- a/tests/ui/feature-gates/feature-gate-repr128.rs
+++ /dev/null
@@ -1,6 +0,0 @@
-#[repr(u128)]
-enum A { //~ ERROR repr with 128-bit type is unstable
-    A(u64)
-}
-
-fn main() {}
diff --git a/tests/ui/feature-gates/feature-gate-repr128.stderr b/tests/ui/feature-gates/feature-gate-repr128.stderr
deleted file mode 100644
index 2607032447b39..0000000000000
--- a/tests/ui/feature-gates/feature-gate-repr128.stderr
+++ /dev/null
@@ -1,13 +0,0 @@
-error[E0658]: repr with 128-bit type is unstable
-  --> $DIR/feature-gate-repr128.rs:2:1
-   |
-LL | enum A {
-   | ^^^^^^
-   |
-   = note: see issue #56071 <https://github.com/rust-lang/rust/issues/56071> for more information
-   = help: add `#![feature(repr128)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0658`.
diff --git a/tests/ui/transmutability/enums/repr/should_handle_all.rs b/tests/ui/transmutability/enums/repr/should_handle_all.rs
index dec0126f22d4c..192b7cdcf726f 100644
--- a/tests/ui/transmutability/enums/repr/should_handle_all.rs
+++ b/tests/ui/transmutability/enums/repr/should_handle_all.rs
@@ -1,8 +1,7 @@
 //@ check-pass
 #![crate_type = "lib"]
-#![feature(repr128)]
 #![feature(transmutability)]
-#![allow(dead_code, incomplete_features, non_camel_case_types)]
+#![allow(dead_code, non_camel_case_types)]
 
 mod assert {
     use std::mem::{Assume, TransmuteFrom};