Add diagnostic items for Clippy

Author: samueltardieu

core/src/char/methods.rs

@@ -395,6 +395,7 @@ impl char {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_char_convert", since = "1.67.0")]
+    #[rustc_diagnostic_item = "char_to_digit"]
     #[must_use = "this returns the result of the operation, \
                   without modifying the original"]
     #[inline]

core/src/iter/range.rs

@@ -20,6 +20,7 @@ unsafe_impl_trusted_step![AsciiChar char i8 i16 i32 i64 i128 isize u8 u16 u32 u6
 ///
 /// The *successor* operation moves towards values that compare greater.
 /// The *predecessor* operation moves towards values that compare lesser.
+#[rustc_diagnostic_item = "range_step"]
 #[unstable(feature = "step_trait", issue = "42168")]
 pub trait Step: Clone + PartialOrd + Sized {
     /// Returns the bounds on the number of *successor* steps required to get from `start` to `end`

core/src/macros/mod.rs

@@ -1192,6 +1192,7 @@ pub(crate) mod builtin {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
+    #[rustc_diagnostic_item = "macro_concat"]
     #[macro_export]
     macro_rules! concat {
         ($($e:expr),* $(,)?) => {{ /* compiler built-in */ }};

core/src/mem/mod.rs

@@ -481,6 +481,7 @@ pub fn min_align_of_val<T: ?Sized>(val: &T) -> usize {
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_promotable]
 #[rustc_const_stable(feature = "const_align_of", since = "1.24.0")]
+#[rustc_diagnostic_item = "mem_align_of"]
 pub const fn align_of<T>() -> usize {
     intrinsics::align_of::<T>()
 }

core/src/slice/raw.rs

@@ -198,6 +198,7 @@ pub const unsafe fn from_raw_parts_mut<'a, T>(data: *mut T, len: usize) -> &'a m
 /// Converts a reference to T into a slice of length 1 (without copying).
 #[stable(feature = "from_ref", since = "1.28.0")]
 #[rustc_const_stable(feature = "const_slice_from_ref_shared", since = "1.63.0")]
+#[rustc_diagnostic_item = "slice_from_ref"]
 #[must_use]
 pub const fn from_ref<T>(s: &T) -> &[T] {
     array::from_ref(s)

std/src/io/error.rs

@@ -219,6 +219,7 @@ struct Custom {
 /// the recognized error kinds and fail in those cases.
 #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "io_errorkind")]
 #[allow(deprecated)]
 #[non_exhaustive]
 pub enum ErrorKind {
@@ -562,6 +563,7 @@ impl Error {
     /// let eof_error = Error::from(ErrorKind::UnexpectedEof);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "io_error_new")]
     #[inline(never)]
     pub fn new<E>(kind: ErrorKind, error: E) -> Error
     where