Late night strong mode cleaning.

tests/compiler/dart2js/inference/id_equivalence_test.dart

Index: tests/compiler/dart2js/inference/id_equivalence_test.dart
diff --git a/tests/compiler/dart2js/inference/id_equivalence_test.dart b/tests/compiler/dart2js/inference/id_equivalence_test.dart
index 033e6909062e4dfe0394d622ef8b04ffd88cad06..73e1725f482b760ba5ce8fe9560ed54205edcf95 100644
--- a/tests/compiler/dart2js/inference/id_equivalence_test.dart
+++ b/tests/compiler/dart2js/inference/id_equivalence_test.dart
@@ -55,7 +55,8 @@ void checkMemberEquivalence(
     }
   }
 
-  elementMap.forEach((Id id, AstElement element) {
+  elementMap.forEach((Id id, _element) {
+    AstElement element = _element;
     ir.Node irNode = irMap[id];
     Expect.equals(kernel.elementToIr(element), irNode,
         "Element mismatch on $id = $element");