Auto merge of #118947 - Bryanskiy:delegStep1, r=petrochenkov,lcnr

Delegation implementation: step 1

See https://github.com/rust-lang/rust/issues/118212 for more details.

r? `@petrochenkov`

src/tools/clippy/clippy_lints/src/dereference.rs

@@ -830,6 +830,7 @@ impl TyCoercionStability {
                 | TyKind::Infer
                 | TyKind::Typeof(..)
                 | TyKind::TraitObject(..)
+                | TyKind::InferDelegation(..)
                 | TyKind::Err(_) => Self::Reborrow,
             };
         }

src/tools/clippy/clippy_utils/src/hir_utils.rs

@@ -1108,7 +1108,7 @@ impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
             TyKind::Typeof(anon_const) => {
                 self.hash_body(anon_const.body);
             },
-            TyKind::Err(_) | TyKind::Infer | TyKind::Never => {},
+            TyKind::Err(_) | TyKind::Infer | TyKind::Never | TyKind::InferDelegation(..) => {},
         }
     }
 

src/tools/rustfmt/src/items.rs

@@ -728,7 +728,9 @@ impl<'a> FmtVisitor<'a> {
                 (Const(..), Const(..)) | (MacCall(..), MacCall(..)) => {
                     a.ident.as_str().cmp(b.ident.as_str())
                 }
-                (Fn(..), Fn(..)) => a.span.lo().cmp(&b.span.lo()),
+                (Fn(..), Fn(..)) | (Delegation(..), Delegation(..)) => {
+                    a.span.lo().cmp(&b.span.lo())
+                }
                 (Type(ty), _) if is_type(&ty.ty) => Ordering::Less,
                 (_, Type(ty)) if is_type(&ty.ty) => Ordering::Greater,
                 (Type(..), _) => Ordering::Less,
@@ -737,6 +739,8 @@ impl<'a> FmtVisitor<'a> {
                 (_, Const(..)) => Ordering::Greater,
                 (MacCall(..), _) => Ordering::Less,
                 (_, MacCall(..)) => Ordering::Greater,
+                (Delegation(..), _) => Ordering::Less,
+                (_, Delegation(..)) => Ordering::Greater,
             });
             let mut prev_kind = None;
             for (buf, item) in buffer {

src/tools/rustfmt/src/visitor.rs

@@ -592,6 +592,11 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
                     );
                     self.push_rewrite(item.span, rewrite);
                 }
+                ast::ItemKind::Delegation(..) => {
+                    // TODO: rewrite delegation items once syntax is established.
+                    // For now, leave the contents of the Span unformatted.
+                    self.push_rewrite(item.span, None)
+                }
             };
         }
         self.skip_context = skip_context_saved;

src/tools/tidy/src/ui_tests.rs

@@ -11,7 +11,7 @@ use std::path::{Path, PathBuf};
 const ENTRY_LIMIT: usize = 900;
 // FIXME: The following limits should be reduced eventually.
 const ISSUES_ENTRY_LIMIT: usize = 1849;
-const ROOT_ENTRY_LIMIT: usize = 869;
+const ROOT_ENTRY_LIMIT: usize = 870;
 
 const EXPECTED_TEST_FILE_EXTENSIONS: &[&str] = &[
     "rs",     // test source files