[ci] Roll pinned nightly toolchain

Cargo.toml

@@ -46,7 +46,7 @@ zerocopy-panic-in-const = "1.57.0"
 [package.metadata.ci]
 # The versions of the stable and nightly compiler toolchains to use in CI.
 pinned-stable = "1.78.0"
-pinned-nightly = "nightly-2024-05-20"
+pinned-nightly = "nightly-2024-05-21"
 
 [package.metadata.docs.rs]
 all-features = true

tests/ui-nightly/transmute-mut-src-dst-not-references.stderr

@@ -13,3 +13,15 @@ help: consider mutably borrowing here
    |
 17 | const SRC_DST_NOT_REFERENCES: &mut usize = transmute_mut!(&mut 0usize);
    |                                                           ++++
+
+warning: never type fallback affects this call to an `unsafe` function
+  --> tests/ui-nightly/transmute-mut-src-dst-not-references.rs:17:44
+   |
+17 | const SRC_DST_NOT_REFERENCES: &mut usize = transmute_mut!(0usize);
+   |                                            ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
+   = help: specify the type explicitly
+   = note: `#[warn(never_type_fallback_flowing_into_unsafe)]` on by default
+   = note: this warning originates in the macro `$crate::assert_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui-nightly/transmute-mut-src-immutable.stderr

@@ -9,3 +9,15 @@ error[E0308]: mismatched types
    |
    = note: expected mutable reference `&mut _`
                       found reference `&u8`
+
+warning: never type fallback affects this call to an `unsafe` function
+  --> tests/ui-nightly/transmute-mut-src-immutable.rs:17:22
+   |
+17 |     let _: &mut u8 = transmute_mut!(&0u8);
+   |                      ^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
+   = help: specify the type explicitly
+   = note: `#[warn(never_type_fallback_flowing_into_unsafe)]` on by default
+   = note: this warning originates in the macro `$crate::assert_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui-nightly/transmute-mut-src-not-a-reference.stderr

@@ -13,3 +13,15 @@ help: consider mutably borrowing here
    |
 17 | const SRC_NOT_A_REFERENCE: &mut u8 = transmute_mut!(&mut 0usize);
    |                                                     ++++
+
+warning: never type fallback affects this call to an `unsafe` function
+  --> tests/ui-nightly/transmute-mut-src-not-a-reference.rs:17:38
+   |
+17 | const SRC_NOT_A_REFERENCE: &mut u8 = transmute_mut!(0usize);
+   |                                      ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
+   = help: specify the type explicitly
+   = note: `#[warn(never_type_fallback_flowing_into_unsafe)]` on by default
+   = note: this warning originates in the macro `$crate::assert_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui-nightly/transmute-ref-src-dst-not-references.stderr

@@ -76,3 +76,26 @@ note: function defined here
    | pub const fn must_use<T>(t: T) -> T {
    |              ^^^^^^^^
    = note: this error originates in the macro `transmute_ref` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+warning: never type fallback affects this call to an `unsafe` function
+  --> tests/ui-nightly/transmute-ref-src-dst-not-references.rs:17:39
+   |
+17 | const SRC_DST_NOT_REFERENCES: usize = transmute_ref!(0usize);
+   |                                       ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
+   = help: specify the type explicitly
+   = note: `#[warn(never_type_fallback_flowing_into_unsafe)]` on by default
+   = note: this warning originates in the macro `$crate::assert_size_eq` which comes from the expansion of the macro `transmute_ref` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+warning: never type fallback affects this call to an `unsafe` function
+  --> tests/ui-nightly/transmute-ref-src-dst-not-references.rs:17:39
+   |
+17 | const SRC_DST_NOT_REFERENCES: usize = transmute_ref!(0usize);
+   |                                       ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
+   = help: specify the type explicitly
+   = note: this warning originates in the macro `transmute_ref` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui-nightly/transmute-ref-src-not-a-reference.stderr

@@ -13,3 +13,26 @@ help: consider borrowing here
    |
 17 | const SRC_NOT_A_REFERENCE: &u8 = transmute_ref!(&0usize);
    |                                                 +
+
+warning: never type fallback affects this call to an `unsafe` function
+  --> tests/ui-nightly/transmute-ref-src-not-a-reference.rs:17:34
+   |
+17 | const SRC_NOT_A_REFERENCE: &u8 = transmute_ref!(0usize);
+   |                                  ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
+   = help: specify the type explicitly
+   = note: `#[warn(never_type_fallback_flowing_into_unsafe)]` on by default
+   = note: this warning originates in the macro `$crate::assert_size_eq` which comes from the expansion of the macro `transmute_ref` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+warning: never type fallback affects this call to an `unsafe` function
+  --> tests/ui-nightly/transmute-ref-src-not-a-reference.rs:17:34
+   |
+17 | const SRC_NOT_A_REFERENCE: &u8 = transmute_ref!(0usize);
+   |                                  ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
+   = help: specify the type explicitly
+   = note: this warning originates in the macro `transmute_ref` (in Nightly builds, run with -Z macro-backtrace for more info)