Reorder fields in hir::ItemKind variants.

Specifically `TyAlias`, `Enum`, `Struct`, `Union`. So the fields match
the textual order in the source code.

The interesting part of the change is in
`compiler/rustc_hir/src/hir.rs`. The rest is extremely mechanical
refactoring.

Author: nnethercote

clippy_lints/src/arbitrary_source_item_ordering.rs

@@ -272,7 +272,7 @@ impl<'tcx> LateLintPass<'tcx> for ArbitrarySourceItemOrdering {
             return;
         }
         match &item.kind {
-            ItemKind::Enum(_, enum_def, _generics) if self.enable_ordering_for_enum => {
+            ItemKind::Enum(_, _generics, enum_def) if self.enable_ordering_for_enum => {
                 let mut cur_v: Option<&Variant<'_>> = None;
                 for variant in enum_def.variants {
                     if variant.span.in_external_macro(cx.sess().source_map()) {
@@ -288,7 +288,7 @@ impl<'tcx> LateLintPass<'tcx> for ArbitrarySourceItemOrdering {
                     cur_v = Some(variant);
                 }
             },
-            ItemKind::Struct(_, VariantData::Struct { fields, .. }, _generics) if self.enable_ordering_for_struct => {
+            ItemKind::Struct(_, _generics, VariantData::Struct { fields, .. }) if self.enable_ordering_for_struct => {
                 let mut cur_f: Option<&FieldDef<'_>> = None;
                 for field in *fields {
                     if field.span.in_external_macro(cx.sess().source_map()) {

clippy_lints/src/empty_with_brackets.rs

@@ -92,7 +92,7 @@ impl_lint_pass!(EmptyWithBrackets => [EMPTY_STRUCTS_WITH_BRACKETS, EMPTY_ENUM_VA
 
 impl LateLintPass<'_> for EmptyWithBrackets {
     fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
-        if let ItemKind::Struct(ident, var_data, _) = &item.kind
+        if let ItemKind::Struct(ident, _, var_data) = &item.kind
             && !item.span.from_expansion()
             && has_brackets(var_data)
             && let span_after_ident = item.span.with_lo(ident.span.hi())

clippy_lints/src/enum_clike.rs

@@ -38,7 +38,7 @@ impl<'tcx> LateLintPass<'tcx> for UnportableVariant {
         if cx.tcx.data_layout.pointer_size.bits() != 64 {
             return;
         }
-        if let ItemKind::Enum(_, def, _) = &item.kind {
+        if let ItemKind::Enum(_, _, def) = &item.kind {
             for var in def.variants {
                 if let Some(anon_const) = &var.disr_expr {
                     let def_id = cx.tcx.hir_body_owner_def_id(anon_const.body);

clippy_lints/src/excessive_bools.rs

@@ -127,7 +127,7 @@ fn check_fn_decl(cx: &LateContext<'_>, decl: &FnDecl<'_>, sp: Span, max: u64) {
 
 impl<'tcx> LateLintPass<'tcx> for ExcessiveBools {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) {
-        if let ItemKind::Struct(_, variant_data, _) = &item.kind
+        if let ItemKind::Struct(_, _, variant_data) = &item.kind
             && variant_data.fields().len() as u64 > self.max_struct_bools
             && has_n_bools(
                 variant_data.fields().iter().map(|field| field.ty),

clippy_lints/src/exhaustive_items.rs

@@ -76,7 +76,7 @@ impl LateLintPass<'_> for ExhaustiveItems {
                 "exported enums should not be exhaustive",
                 [].as_slice(),
             ),
-            ItemKind::Struct(_, v, ..) => (
+            ItemKind::Struct(_, _, v) => (
                 EXHAUSTIVE_STRUCTS,
                 "exported structs should not be exhaustive",
                 v.fields(),

clippy_lints/src/functions/result.rs

@@ -103,7 +103,7 @@ fn check_result_large_err<'tcx>(cx: &LateContext<'tcx>, err_ty: Ty<'tcx>, hir_ty
             .did()
             .as_local()
         && let hir::Node::Item(item) = cx.tcx.hir_node_by_def_id(local_def_id)
-        && let hir::ItemKind::Enum(_, ref def, _) = item.kind
+        && let hir::ItemKind::Enum(_, _, ref def) = item.kind
     {
         let variants_size = AdtVariantInfo::new(cx, *adt, subst);
         if let Some((first_variant, variants)) = variants_size.split_first()

clippy_lints/src/item_name_repetitions.rs

@@ -535,10 +535,10 @@ impl LateLintPass<'_> for ItemNameRepetitions {
 
         if span_is_local(item.span) {
             match item.kind {
-                ItemKind::Enum(_, def, _) => {
+                ItemKind::Enum(_, _, def) => {
                     self.check_variants(cx, item, &def);
                 },
-                ItemKind::Struct(_, VariantData::Struct { fields, .. }, _) => {
+                ItemKind::Struct(_, _, VariantData::Struct { fields, .. }) => {
                     self.check_fields(cx, item, fields);
                 },
                 _ => (),

clippy_lints/src/large_const_arrays.rs

@@ -48,7 +48,7 @@ impl_lint_pass!(LargeConstArrays => [LARGE_CONST_ARRAYS]);
 
 impl<'tcx> LateLintPass<'tcx> for LargeConstArrays {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
-        if let ItemKind::Const(ident, _, generics, _) = &item.kind
+        if let ItemKind::Const(ident, generics, _, _) = &item.kind
             // Since static items may not have generics, skip generic const items.
             // FIXME(generic_const_items): I don't think checking `generics.hwcp` suffices as it
             // doesn't account for empty where-clauses that only consist of keyword `where` IINM.

clippy_lints/src/large_enum_variant.rs

@@ -73,7 +73,7 @@ impl_lint_pass!(LargeEnumVariant => [LARGE_ENUM_VARIANT]);
 
 impl<'tcx> LateLintPass<'tcx> for LargeEnumVariant {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &Item<'tcx>) {
-        if let ItemKind::Enum(ident, ref def, _) = item.kind
+        if let ItemKind::Enum(ident, _, ref def) = item.kind
             && let ty = cx.tcx.type_of(item.owner_id).instantiate_identity()
             && let ty::Adt(adt, subst) = ty.kind()
             && adt.variants().len() > 1

clippy_lints/src/manual_non_exhaustive.rs

@@ -87,7 +87,7 @@ impl<'tcx> LateLintPass<'tcx> for ManualNonExhaustive {
         }
 
         match item.kind {
-            ItemKind::Enum(_, def, _) if def.variants.len() > 1 => {
+            ItemKind::Enum(_, _, def) if def.variants.len() > 1 => {
                 let iter = def.variants.iter().filter_map(|v| {
                     (matches!(v.data, VariantData::Unit(_, _)) && is_doc_hidden(cx.tcx.hir_attrs(v.hir_id)))
                         .then_some((v.def_id, v.span))
@@ -98,7 +98,7 @@ impl<'tcx> LateLintPass<'tcx> for ManualNonExhaustive {
                     self.potential_enums.push((item.owner_id.def_id, id, item.span, span));
                 }
             },
-            ItemKind::Struct(_, variant_data, _) => {
+            ItemKind::Struct(_, _, variant_data) => {
                 let fields = variant_data.fields();
                 let private_fields = fields
                     .iter()

clippy_lints/src/missing_fields_in_debug.rs

@@ -225,7 +225,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingFieldsInDebug {
             && let typeck_results = cx.tcx.typeck_body(*body_id)
             && should_lint(cx, typeck_results, block)
             // we intentionally only lint structs, see lint description
-            && let ItemKind::Struct(_, data, _) = &self_item.kind
+            && let ItemKind::Struct(_, _, data) = &self_item.kind
         {
             check_struct(cx, typeck_results, block, self_ty, item, data);
         }

clippy_lints/src/non_std_lazy_statics.rs

@@ -187,7 +187,7 @@ struct LazyInfo {
 impl LazyInfo {
     fn from_item(cx: &LateContext<'_>, item: &Item<'_>) -> Option<Self> {
         // Check if item is a `once_cell:sync::Lazy` static.
-        if let ItemKind::Static(_, ty, _, body_id) = item.kind
+        if let ItemKind::Static(_, _, ty, body_id) = item.kind
             && let Some(path_def_id) = path_def_id(cx, ty)
             && let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = ty.kind
             && paths::ONCE_CELL_SYNC_LAZY.matches(cx, path_def_id)

clippy_lints/src/pub_underscore_fields.rs

@@ -58,7 +58,7 @@ impl PubUnderscoreFields {
 impl<'tcx> LateLintPass<'tcx> for PubUnderscoreFields {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
         // This lint only pertains to structs.
-        let ItemKind::Struct(_, variant_data, _) = &item.kind else {
+        let ItemKind::Struct(_, _, variant_data) = &item.kind else {
             return;
         };
 

clippy_lints/src/trailing_empty_array.rs

@@ -57,7 +57,7 @@ impl<'tcx> LateLintPass<'tcx> for TrailingEmptyArray {
 }
 
 fn is_struct_with_trailing_zero_sized_array<'tcx>(cx: &LateContext<'tcx>, item: &Item<'tcx>) -> bool {
-    if let ItemKind::Struct(_, data, _) = &item.kind
+    if let ItemKind::Struct(_, _, data) = &item.kind
         && let Some(last_field) = data.fields().last()
         && let field_ty = cx.tcx.normalize_erasing_regions(
             cx.typing_env(),

clippy_lints/src/types/mod.rs

@@ -447,7 +447,7 @@ impl<'tcx> LateLintPass<'tcx> for Types {
         let is_exported = cx.effective_visibilities.is_exported(item.owner_id.def_id);
 
         match item.kind {
-            ItemKind::Static(_, ty, _, _) | ItemKind::Const(_, ty, _, _) => self.check_ty(
+            ItemKind::Static(_, _, ty, _) | ItemKind::Const(_, _, ty, _) => self.check_ty(
                 cx,
                 ty,
                 CheckTyContext {

clippy_lints/src/upper_case_acronyms.rs

@@ -134,7 +134,7 @@ impl LateLintPass<'_> for UpperCaseAcronyms {
             ItemKind::TyAlias(ident, ..) | ItemKind::Struct(ident, ..) | ItemKind::Trait(_, _, ident, ..) => {
                 check_ident(cx, &ident, it.hir_id(), self.upper_case_acronyms_aggressive);
             },
-            ItemKind::Enum(ident, ref enumdef, _) => {
+            ItemKind::Enum(ident, _, ref enumdef) => {
                 check_ident(cx, &ident, it.hir_id(), self.upper_case_acronyms_aggressive);
                 // check enum variants separately because again we only want to lint on private enums and
                 // the fn check_variant does not know about the vis of the enum of its variants

clippy_utils/src/check_proc_macro.rs

@@ -249,7 +249,7 @@ fn item_search_pat(item: &Item<'_>) -> (Pat, Pat) {
         ItemKind::ForeignMod { .. } => (Pat::Str("extern"), Pat::Str("}")),
         ItemKind::TyAlias(..) => (Pat::Str("type"), Pat::Str(";")),
         ItemKind::Enum(..) => (Pat::Str("enum"), Pat::Str("}")),
-        ItemKind::Struct(_, VariantData::Struct { .. }, _) => (Pat::Str("struct"), Pat::Str("}")),
+        ItemKind::Struct(_, _, VariantData::Struct { .. }) => (Pat::Str("struct"), Pat::Str("}")),
         ItemKind::Struct(..) => (Pat::Str("struct"), Pat::Str(";")),
         ItemKind::Union(..) => (Pat::Str("union"), Pat::Str("}")),
         ItemKind::Trait(_, Safety::Unsafe, ..)

clippy_utils/src/lib.rs

@@ -2362,7 +2362,7 @@ fn with_test_item_names(tcx: TyCtxt<'_>, module: LocalModDefId, f: impl FnOnce(&
             for id in tcx.hir_module_free_items(module) {
                 if matches!(tcx.def_kind(id.owner_id), DefKind::Const)
                     && let item = tcx.hir_item(id)
-                    && let ItemKind::Const(ident, ty, _generics, _body) = item.kind
+                    && let ItemKind::Const(ident, _generics, ty, _body) = item.kind
                     && let TyKind::Path(QPath::Resolved(_, path)) = ty.kind
                         // We could also check for the type name `test::TestDescAndFn`
                         && let Res::Def(DefKind::Struct, _) = path.res