Rollup merge of #138285 - beetrees:repr128-stable, r=traviscross,bjorn3

Stabilize `repr128`

## Stabilisation report

The `repr128` feature ([tracking issue](https://github.com/rust-lang/rust/issues/56071)) allows the use of `#[repr(u128)]` and `#[repr(i128)]` on enums in the same way that other primitive representations such as `#[repr(u64)]` can be used. For example:

```rust
#[repr(u128)]
enum Foo {
    One = 1,
    Two,
    Big = u128::MAX,
}

#[repr(i128)]
enum Bar {
    HasThing(u16) = 42,
    HasSomethingElse(i64) = u64::MAX as i128 + 1,
    HasNothing,
}
```

This is the final part of adding 128-bit integers to Rust ([RFC 1504](https://rust-lang.github.io/rfcs/1504-int128.html)); all other parts of 128-bit integer support were stabilised in #49101 back in 2018.

From a design perspective, `#[repr(u128)]`/`#[repr(i128)]` function like `#[repr(u64)]`/`#[repr(i64)]` but for 128-bit integers instead of 64-bit integers. The only differences are:

- FFI safety: as `u128`/`i128` are not currently considered FFI safe, neither are `#[repr(u128)]`/`#[repr(i128)]` enums (I discovered this wasn't the case while drafting this stabilisation report, so I have submitted #138282 to fix this).
- Debug info: while none of the major debuggers currently support 128-bit integers, as of LLVM 20 `rustc` will emit valid debuginfo for both DWARF and PDB (PDB makes use of the same natvis that is also used for all enums with fields, whereas DWARF has native support).

Tests for `#[repr(u128)]`/`#[repr(i128)]` enums include:
- [ui/enum-discriminant/repr128.rs](https://github.com/rust-lang/rust/blob/385970f0c1fd0c09bac426b02f38300c0b1ba9a2/tests/ui/enum-discriminant/repr128.rs): checks that 128-bit enum discriminants have the correct values.
- [debuginfo/msvc-pretty-enums.rs](https://github.com/rust-lang/rust/blob/385970f0c1fd0c09bac426b02f38300c0b1ba9a2/tests/debuginfo/msvc-pretty-enums.rs): checks the PDB debuginfo is correct.
- [run-make/repr128-dwarf](https://github.com/rust-lang/rust/blob/385970f0c1fd0c09bac426b02f38300c0b1ba9a2/tests/run-make/repr128-dwarf/rmake.rs): checks the DWARF debuginfo is correct.

Stabilising this feature does not require any changes to the Rust Reference as [the documentation on primitive representations](https://doc.rust-lang.org/nightly/reference/type-layout.html#r-layout.repr.primitive.intro) already includes `u128` and `i128`.

Closes #56071
Closes https://github.com/rust-lang/reference/issues/1368

r? lang

```@rustbot``` label +I-lang-nominated +T-lang

21 files changed, 43 insertions, 132 deletions

diff --git a/tests/codegen/enum/enum-u128.rs b/tests/codegen/enum/enum-u128.rs
index ecdff3c5ce3..2676669f3e3 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 06bc25dc5d5..aa6629ef1e1 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 e42be8ac06d..81390567c2b 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 3372ae2f2a6..00131b0116d 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 9842ab4a342..a8a414fd72e 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 c84181334e3..e98271b7c80 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 a3ec1b28e5c..b1feff3c59e 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 9b1505b5c46..00000000000
--- 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 fc7bbd06284..00000000000
--- 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 e98532c1207..5e71972c280 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 2eef930c394..00000000000
--- 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
index 574a4b3ad5a..2bb9725fb77 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 075ff7a7676..d59a5b3e256 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 da8d75c11af..00000000000
--- 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 9c9b95d70a7..e51674cdf92 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 e1e812940ec..ae7ecbbc5cb 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 0290874dd27..00000000000
--- 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 2607032447b..00000000000
--- 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/lint/lint-ctypes-enum.rs b/tests/ui/lint/lint-ctypes-enum.rs
index b2ef27b833b..612da86c956 100644
--- a/tests/ui/lint/lint-ctypes-enum.rs
+++ b/tests/ui/lint/lint-ctypes-enum.rs
@@ -2,8 +2,6 @@
 #![deny(improper_ctypes)]
 #![feature(ptr_internals)]
 #![feature(transparent_unions)]
-#![feature(repr128)]
-#![allow(incomplete_features)]
 
 use std::num;
 
diff --git a/tests/ui/lint/lint-ctypes-enum.stderr b/tests/ui/lint/lint-ctypes-enum.stderr
index d5fc844f756..50a6f526f26 100644
--- a/tests/ui/lint/lint-ctypes-enum.stderr
+++ b/tests/ui/lint/lint-ctypes-enum.stderr
@@ -1,5 +1,5 @@
 error: `extern` block uses type `U`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:84:14
+  --> $DIR/lint-ctypes-enum.rs:82:14
    |
 LL |     fn uf(x: U);
    |              ^ not FFI-safe
@@ -7,7 +7,7 @@ LL |     fn uf(x: U);
    = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
    = note: enum has no representation hint
 note: the type is defined here
-  --> $DIR/lint-ctypes-enum.rs:11:1
+  --> $DIR/lint-ctypes-enum.rs:9:1
    |
 LL | enum U {
    | ^^^^^^
@@ -18,7 +18,7 @@ LL | #![deny(improper_ctypes)]
    |         ^^^^^^^^^^^^^^^
 
 error: `extern` block uses type `B`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:85:14
+  --> $DIR/lint-ctypes-enum.rs:83:14
    |
 LL |     fn bf(x: B);
    |              ^ not FFI-safe
@@ -26,13 +26,13 @@ LL |     fn bf(x: B);
    = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
    = note: enum has no representation hint
 note: the type is defined here
-  --> $DIR/lint-ctypes-enum.rs:14:1
+  --> $DIR/lint-ctypes-enum.rs:12:1
    |
 LL | enum B {
    | ^^^^^^
 
 error: `extern` block uses type `T`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:86:14
+  --> $DIR/lint-ctypes-enum.rs:84:14
    |
 LL |     fn tf(x: T);
    |              ^ not FFI-safe
@@ -40,39 +40,39 @@ LL |     fn tf(x: T);
    = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
    = note: enum has no representation hint
 note: the type is defined here
-  --> $DIR/lint-ctypes-enum.rs:18:1
+  --> $DIR/lint-ctypes-enum.rs:16:1
    |
 LL | enum T {
    | ^^^^^^
 
 error: `extern` block uses type `U128`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:90:21
+  --> $DIR/lint-ctypes-enum.rs:88:21
    |
 LL |     fn repr_u128(x: U128);
    |                     ^^^^ not FFI-safe
    |
    = note: 128-bit integers don't currently have a known stable ABI
 note: the type is defined here
-  --> $DIR/lint-ctypes-enum.rs:46:1
+  --> $DIR/lint-ctypes-enum.rs:44:1
    |
 LL | enum U128 {
    | ^^^^^^^^^
 
 error: `extern` block uses type `I128`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:91:21
+  --> $DIR/lint-ctypes-enum.rs:89:21
    |
 LL |     fn repr_i128(x: I128);
    |                     ^^^^ not FFI-safe
    |
    = note: 128-bit integers don't currently have a known stable ABI
 note: the type is defined here
-  --> $DIR/lint-ctypes-enum.rs:53:1
+  --> $DIR/lint-ctypes-enum.rs:51:1
    |
 LL | enum I128 {
    | ^^^^^^^^^
 
 error: `extern` block uses type `u128`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:100:31
+  --> $DIR/lint-ctypes-enum.rs:98:31
    |
 LL |     fn option_nonzero_u128(x: Option<num::NonZero<u128>>);
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -80,7 +80,7 @@ LL |     fn option_nonzero_u128(x: Option<num::NonZero<u128>>);
    = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `i128`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:107:31
+  --> $DIR/lint-ctypes-enum.rs:105:31
    |
 LL |     fn option_nonzero_i128(x: Option<num::NonZero<i128>>);
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -88,7 +88,7 @@ LL |     fn option_nonzero_i128(x: Option<num::NonZero<i128>>);
    = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `Option<TransparentUnion<NonZero<u8>>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:112:36
+  --> $DIR/lint-ctypes-enum.rs:110:36
    |
 LL |     fn option_transparent_union(x: Option<TransparentUnion<num::NonZero<u8>>>);
    |                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -97,7 +97,7 @@ LL |     fn option_transparent_union(x: Option<TransparentUnion<num::NonZero<u8>
    = note: enum has no representation hint
 
 error: `extern` block uses type `Option<Rust<NonZero<u8>>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:114:28
+  --> $DIR/lint-ctypes-enum.rs:112:28
    |
 LL |     fn option_repr_rust(x: Option<Rust<num::NonZero<u8>>>);
    |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -106,7 +106,7 @@ LL |     fn option_repr_rust(x: Option<Rust<num::NonZero<u8>>>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `Option<u8>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:115:21
+  --> $DIR/lint-ctypes-enum.rs:113:21
    |
 LL |     fn option_u8(x: Option<u8>);
    |                     ^^^^^^^^^^ not FFI-safe
@@ -115,7 +115,7 @@ LL |     fn option_u8(x: Option<u8>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `u128`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:125:33
+  --> $DIR/lint-ctypes-enum.rs:123:33
    |
 LL |     fn result_nonzero_u128_t(x: Result<num::NonZero<u128>, ()>);
    |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -123,7 +123,7 @@ LL |     fn result_nonzero_u128_t(x: Result<num::NonZero<u128>, ()>);
    = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `i128`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:132:33
+  --> $DIR/lint-ctypes-enum.rs:130:33
    |
 LL |     fn result_nonzero_i128_t(x: Result<num::NonZero<i128>, ()>);
    |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -131,7 +131,7 @@ LL |     fn result_nonzero_i128_t(x: Result<num::NonZero<i128>, ()>);
    = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `Result<TransparentUnion<NonZero<u8>>, ()>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:137:38
+  --> $DIR/lint-ctypes-enum.rs:135:38
    |
 LL |     fn result_transparent_union_t(x: Result<TransparentUnion<num::NonZero<u8>>, ()>);
    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -140,7 +140,7 @@ LL |     fn result_transparent_union_t(x: Result<TransparentUnion<num::NonZero<u
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<Rust<NonZero<u8>>, ()>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:139:30
+  --> $DIR/lint-ctypes-enum.rs:137:30
    |
 LL |     fn result_repr_rust_t(x: Result<Rust<num::NonZero<u8>>, ()>);
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -149,7 +149,7 @@ LL |     fn result_repr_rust_t(x: Result<Rust<num::NonZero<u8>>, ()>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonZero<u8>, U>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:143:51
+  --> $DIR/lint-ctypes-enum.rs:141:51
    |
 LL |     fn result_1zst_exhaustive_single_variant_t(x: Result<num::NonZero<u8>, U>);
    |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -158,7 +158,7 @@ LL |     fn result_1zst_exhaustive_single_variant_t(x: Result<num::NonZero<u8>,
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonZero<u8>, B>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:145:53
+  --> $DIR/lint-ctypes-enum.rs:143:53
    |
 LL |     fn result_1zst_exhaustive_multiple_variant_t(x: Result<num::NonZero<u8>, B>);
    |                                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -167,7 +167,7 @@ LL |     fn result_1zst_exhaustive_multiple_variant_t(x: Result<num::NonZero<u8>
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonZero<u8>, NonExhaustive>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:147:51
+  --> $DIR/lint-ctypes-enum.rs:145:51
    |
 LL |     fn result_1zst_non_exhaustive_no_variant_t(x: Result<num::NonZero<u8>, NonExhaustive>);
    |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -176,7 +176,7 @@ LL |     fn result_1zst_non_exhaustive_no_variant_t(x: Result<num::NonZero<u8>,
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonZero<u8>, Field>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:150:49
+  --> $DIR/lint-ctypes-enum.rs:148:49
    |
 LL |     fn result_1zst_exhaustive_single_field_t(x: Result<num::NonZero<u8>, Field>);
    |                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -185,7 +185,7 @@ LL |     fn result_1zst_exhaustive_single_field_t(x: Result<num::NonZero<u8>, Fi
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<Result<(), NonZero<u8>>, ()>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:152:30
+  --> $DIR/lint-ctypes-enum.rs:150:30
    |
 LL |     fn result_cascading_t(x: Result<Result<(), num::NonZero<u8>>, ()>);
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -194,7 +194,7 @@ LL |     fn result_cascading_t(x: Result<Result<(), num::NonZero<u8>>, ()>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `u128`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:163:33
+  --> $DIR/lint-ctypes-enum.rs:161:33
    |
 LL |     fn result_nonzero_u128_e(x: Result<(), num::NonZero<u128>>);
    |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -202,7 +202,7 @@ LL |     fn result_nonzero_u128_e(x: Result<(), num::NonZero<u128>>);
    = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `i128`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:170:33
+  --> $DIR/lint-ctypes-enum.rs:168:33
    |
 LL |     fn result_nonzero_i128_e(x: Result<(), num::NonZero<i128>>);
    |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -210,7 +210,7 @@ LL |     fn result_nonzero_i128_e(x: Result<(), num::NonZero<i128>>);
    = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `Result<(), TransparentUnion<NonZero<u8>>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:175:38
+  --> $DIR/lint-ctypes-enum.rs:173:38
    |
 LL |     fn result_transparent_union_e(x: Result<(), TransparentUnion<num::NonZero<u8>>>);
    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -219,7 +219,7 @@ LL |     fn result_transparent_union_e(x: Result<(), TransparentUnion<num::NonZe
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<(), Rust<NonZero<u8>>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:177:30
+  --> $DIR/lint-ctypes-enum.rs:175:30
    |
 LL |     fn result_repr_rust_e(x: Result<(), Rust<num::NonZero<u8>>>);
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -228,7 +228,7 @@ LL |     fn result_repr_rust_e(x: Result<(), Rust<num::NonZero<u8>>>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<U, NonZero<u8>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:181:51
+  --> $DIR/lint-ctypes-enum.rs:179:51
    |
 LL |     fn result_1zst_exhaustive_single_variant_e(x: Result<U, num::NonZero<u8>>);
    |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -237,7 +237,7 @@ LL |     fn result_1zst_exhaustive_single_variant_e(x: Result<U, num::NonZero<u8
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<B, NonZero<u8>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:183:53
+  --> $DIR/lint-ctypes-enum.rs:181:53
    |
 LL |     fn result_1zst_exhaustive_multiple_variant_e(x: Result<B, num::NonZero<u8>>);
    |                                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -246,7 +246,7 @@ LL |     fn result_1zst_exhaustive_multiple_variant_e(x: Result<B, num::NonZero<
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonExhaustive, NonZero<u8>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:185:51
+  --> $DIR/lint-ctypes-enum.rs:183:51
    |
 LL |     fn result_1zst_non_exhaustive_no_variant_e(x: Result<NonExhaustive, num::NonZero<u8>>);
    |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -255,7 +255,7 @@ LL |     fn result_1zst_non_exhaustive_no_variant_e(x: Result<NonExhaustive, num
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<Field, NonZero<u8>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:188:49
+  --> $DIR/lint-ctypes-enum.rs:186:49
    |
 LL |     fn result_1zst_exhaustive_single_field_e(x: Result<Field, num::NonZero<u8>>);
    |                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -264,7 +264,7 @@ LL |     fn result_1zst_exhaustive_single_field_e(x: Result<Field, num::NonZero<
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<(), Result<(), NonZero<u8>>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:190:30
+  --> $DIR/lint-ctypes-enum.rs:188:30
    |
 LL |     fn result_cascading_e(x: Result<(), Result<(), num::NonZero<u8>>>);
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -273,7 +273,7 @@ LL |     fn result_cascading_e(x: Result<(), Result<(), num::NonZero<u8>>>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<(), ()>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:192:27
+  --> $DIR/lint-ctypes-enum.rs:190:27
    |
 LL |     fn result_unit_t_e(x: Result<(), ()>);
    |                           ^^^^^^^^^^^^^^ not FFI-safe
diff --git a/tests/ui/transmutability/enums/repr/should_handle_all.rs b/tests/ui/transmutability/enums/repr/should_handle_all.rs
index dec0126f22d..192b7cdcf72 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};