Auto merge of #39500 - michaelwoerister:fix-ich-testing, r=nikomatsakis

Let the dep-tracking test framework check that all #[rustc_dirty] attrs have been actually checked

r? @nikomatsakis

src/librustc/hir/intravisit.rs

@@ -914,6 +914,7 @@ pub fn walk_decl<'v, V: Visitor<'v>>(visitor: &mut V, declaration: &'v Decl) {
 
 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
     visitor.visit_id(expression.id);
+    walk_list!(visitor, visit_attribute, expression.attrs.iter());
     match expression.node {
         ExprBox(ref subexpression) => {
             visitor.visit_expr(subexpression)