requested/proposed changes

compiler/rustc_span/src/symbol.rs

@@ -169,10 +169,12 @@ symbols! {
         Option,
         Ord,
         Ordering,
+        OsString,
         Output,
         Param,
         PartialEq,
         PartialOrd,
+        PathBuf,
         Pending,
         Pin,
         Poll,
@@ -198,6 +200,7 @@ symbols! {
         StructuralPartialEq,
         Sync,
         Target,
+        ToOwned,
         Try,
         Ty,
         TyCtxt,
@@ -796,7 +799,6 @@ symbols! {
         options,
         or,
         or_patterns,
-        os_string_type,
         other,
         out,
         overlapping_marker_traits,
@@ -825,7 +827,6 @@ symbols! {
         pat2018,
         pat2021,
         path,
-        path_buf_type,
         pattern_parentheses,
         phantom_data,
         pin,
@@ -1086,7 +1087,6 @@ symbols! {
         slice,
         slice_alloc,
         slice_patterns,
-        slice_to_vec_method,
         slice_u8,
         slice_u8_alloc,
         slicing_syntax,
@@ -1162,7 +1162,6 @@ symbols! {
         then_with,
         thread,
         thread_local,
-        to_owned_trait,
         tool_attributes,
         tool_lints,
         trace_macros,

library/alloc/src/borrow.rs

@@ -32,7 +32,7 @@ where
 /// to `T`. The `ToOwned` trait generalizes `Clone` to construct owned data
 /// from any borrow of a given type.
 #[stable(feature = "rust1", since = "1.0.0")]
-#[cfg_attr(not(test), rustc_diagnostic_item = "to_owned_trait")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "ToOwned")]
 pub trait ToOwned {
     /// The resulting type after obtaining ownership.
     #[stable(feature = "rust1", since = "1.0.0")]

library/alloc/src/slice.rs

@@ -220,6 +220,7 @@ mod hack {
 }
 
 #[lang = "slice_alloc"]
+#[cfg_attr(not(test), rustc_diagnostic_item = "slice")]
 #[cfg(not(test))]
 impl<T> [T] {
     /// Sorts the slice.
@@ -442,7 +443,6 @@ impl<T> [T] {
     /// // Here, `s` and `x` can be modified independently.
     /// ```
     #[rustc_conversion_suggestion]
-    #[rustc_diagnostic_item = "slice_to_vec_method"]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn to_vec(&self) -> Vec<T>

library/std/src/ffi/os_str.rs

@@ -71,7 +71,7 @@ use crate::sys_common::{AsInner, FromInner, IntoInner};
 /// [`CStr`]: crate::ffi::CStr
 /// [conversions]: super#conversions
 #[derive(Clone)]
-#[cfg_attr(not(test), rustc_diagnostic_item = "os_string_type")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "OsString")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct OsString {
     inner: Buf,

library/std/src/path.rs

@@ -1066,7 +1066,7 @@ impl FusedIterator for Ancestors<'_> {}
 ///
 /// Which method works best depends on what kind of situation you're in.
 #[derive(Clone)]
-#[cfg_attr(not(test), rustc_diagnostic_item = "path_buf_type")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "PathBuf")]
 #[stable(feature = "rust1", since = "1.0.0")]
 // FIXME:
 // `PathBuf::as_mut_vec` current implementation relies