Rollup merge of #78326 - Aaron1011:fix/min-stmt-lints, r=petrochenkov

Split out statement attributes changes from #78306

This is the same as PR https://github.com/rust-lang/rust/pull/78306, but `unused_doc_comments` is modified to explicitly ignore statement items (which preserves the current behavior).

This shouldn't have any user-visible effects, so it can be landed without lang team discussion.

---------
When the 'early' and 'late' visitors visit an attribute target, they
activate any lint attributes (e.g. `#[allow]`) that apply to it.
This can affect warnings emitted on sibiling attributes. For example,
the following code does not produce an `unused_attributes` for
`#[inline]`, since the sibiling `#[allow(unused_attributes)]` suppressed
the warning.

```rust
trait Foo {
    #[allow(unused_attributes)] #[inline] fn first();
    #[inline] #[allow(unused_attributes)] fn second();
}
```

However, we do not do this for statements - instead, the lint attributes
only become active when we visit the struct nested inside `StmtKind`
(e.g. `Item`).

Currently, this is difficult to observe due to another issue - the
`HasAttrs` impl for `StmtKind` ignores attributes for `StmtKind::Item`.
As a result, the `unused_doc_comments` lint will never see attributes on
item statements.

This commit makes two interrelated fixes to the handling of inert
(non-proc-macro) attributes on statements:

* The `HasAttr` impl for `StmtKind` now returns attributes for
  `StmtKind::Item`, treating it just like every other `StmtKind`
  variant. The only place relying on the old behavior was macro
  which has been updated to explicitly ignore attributes on item
  statements. This allows the `unused_doc_comments` lint to fire for
  item statements.
* The `early` and `late` lint visitors now activate lint attributes when
  invoking the callback for `Stmt`. This ensures that a lint
  attribute (e.g. `#[allow(unused_doc_comments)]`) can be applied to
  sibiling attributes on an item statement.

For now, the `unused_doc_comments` lint is explicitly disabled on item
statements, which preserves the current behavior. The exact locatiosn
where this lint should fire are being discussed in PR #78306

compiler/rustc_hir/src/hir.rs

@@ -1101,11 +1101,11 @@ pub enum StmtKind<'hir> {
     Semi(&'hir Expr<'hir>),
 }
 
-impl StmtKind<'hir> {
-    pub fn attrs(&self) -> &'hir [Attribute] {
+impl<'hir> StmtKind<'hir> {
+    pub fn attrs(&self, get_item: impl FnOnce(ItemId) -> &'hir Item<'hir>) -> &'hir [Attribute] {
         match *self {
             StmtKind::Local(ref l) => &l.attrs,
-            StmtKind::Item(_) => &[],
+            StmtKind::Item(ref item_id) => &get_item(*item_id).attrs,
             StmtKind::Expr(ref e) | StmtKind::Semi(ref e) => &e.attrs,
         }
     }