Auto merge of #95977 - FabianWolff:issue-92790-dead-tuple, r=estebank

Warn about dead tuple struct fields

Continuation of #92972. Fixes #92790.

The language team has already commented on this in https://github.com/rust-lang/rust/pull/92972#issuecomment-1021511970; I have incorporated their requests here. Specifically, there is now a new allow-by-default `unused_tuple_struct_fields` lint (name bikesheddable), and fields of unit type are ignored (https://github.com/rust-lang/rust/pull/92972#issuecomment-1021815408), so error messages look like this:
```
error: field is never read: `1`
  --> $DIR/tuple-struct-field.rs:6:21
   |
LL | struct Wrapper(i32, [u8; LEN], String);
   |                     ^^^^^^^^^
   |
help: change the field to unit type to suppress this warning while preserving the field numbering
   |
LL | struct Wrapper(i32, (), String);
   |                     ~~
```
r? `@joshtriplett`

compiler/rustc_passes/src/check_attr.rs

@@ -53,7 +53,7 @@ pub(crate) fn target_from_impl_item<'tcx>(
 #[derive(Clone, Copy)]
 enum ItemLike<'tcx> {
     Item(&'tcx Item<'tcx>),
-    ForeignItem(&'tcx ForeignItem<'tcx>),
+    ForeignItem,
 }
 
 struct CheckAttrVisitor<'tcx> {
@@ -2020,12 +2020,7 @@ impl<'tcx> Visitor<'tcx> for CheckAttrVisitor<'tcx> {
 
     fn visit_foreign_item(&mut self, f_item: &'tcx ForeignItem<'tcx>) {
         let target = Target::from_foreign_item(f_item);
-        self.check_attributes(
-            f_item.hir_id(),
-            f_item.span,
-            target,
-            Some(ItemLike::ForeignItem(f_item)),
-        );
+        self.check_attributes(f_item.hir_id(), f_item.span, target, Some(ItemLike::ForeignItem));
         intravisit::walk_foreign_item(self, f_item)
     }