Fixed failing test + minor cleanup

compiler/rustc_data_structures/src/unord.rs

@@ -62,6 +62,11 @@ impl<T, I: Iterator<Item = T>> UnordItems<T, I> {
         UnordItems(self.0.filter_map(f))
     }
 
+    #[inline]
+    pub fn for_each<F: Fn(T) -> ()>(self, f: F) {
+        self.0.for_each(|x| f(x));
+    }
+
     #[inline]
     pub fn max(self) -> Option<T>
     where