Add diagnostic items for ptr::cast_mut and ptr::from_ref

Author: Urgau

core/src/ptr/const_ptr.rs

@@ -104,6 +104,7 @@ impl<T: ?Sized> *const T {
     /// refactored.
     #[stable(feature = "ptr_const_cast", since = "1.65.0")]
     #[rustc_const_stable(feature = "ptr_const_cast", since = "1.65.0")]
+    #[rustc_diagnostic_item = "ptr_cast_mut"]
     #[inline(always)]
     pub const fn cast_mut(self) -> *mut T {
         self as _

core/src/ptr/mod.rs

@@ -698,6 +698,7 @@ where
 #[inline(always)]
 #[must_use]
 #[unstable(feature = "ptr_from_ref", issue = "106116")]
+#[rustc_diagnostic_item = "ptr_from_ref"]
 pub const fn from_ref<T: ?Sized>(r: &T) -> *const T {
     r
 }