internal: Only intern blocks that declare items

crates/hir-def/src/item_tree/lower.rs

@@ -101,6 +101,34 @@ impl<'a> Ctx<'a> {
         self.tree
     }
 
+    pub(super) fn block_has_items(mut self, block: &ast::BlockExpr) -> bool {
+        let statement_has_item = block
+            .statements()
+            .find_map(|stmt| match stmt {
+                ast::Stmt::Item(item) => self.lower_mod_item(&item),
+                // Macro calls can be both items and expressions. The syntax library always treats
+                // them as expressions here, so we undo that.
+                ast::Stmt::ExprStmt(es) => match es.expr()? {
+                    ast::Expr::MacroExpr(expr) => self.lower_mod_item(&expr.macro_call()?.into()),
+                    _ => None,
+                },
+                _ => None,
+            })
+            .is_some();
+        if statement_has_item {
+            return true;
+        }
+
+        if let Some(ast::Expr::MacroExpr(expr)) = block.tail_expr() {
+            if let Some(call) = expr.macro_call() {
+                if let Some(_) = self.lower_mod_item(&call.into()) {
+                    return true;
+                }
+            }
+        }
+        false
+    }
+
     fn data(&mut self) -> &mut ItemTreeData {
         self.tree.data_mut()
     }