Fix of https://codereview.chromium.org//964553004 .

pkg/compiler/lib/src/closure.dart

Index: pkg/compiler/lib/src/closure.dart
diff --git a/pkg/compiler/lib/src/closure.dart b/pkg/compiler/lib/src/closure.dart
index 29588b88a6b8d1b74777d381c82f8369286c31df..beeadde429bf40d02d36b01d15ea87c65a181cc9 100644
--- a/pkg/compiler/lib/src/closure.dart
+++ b/pkg/compiler/lib/src/closure.dart
@@ -1034,10 +1034,10 @@ class ClosureTranslator extends Visitor {
       // An `await for` loop is enclosed in an implicit try-finally.
       bool oldInTryStatement = inTryStatement;
       inTryStatement = true;
-      node.visitChildren(this);
+      visitLoop(node);
       inTryStatement = oldInTryStatement;
     } else {
-      node.visitChildren(this);
+      visitLoop(node);
     }
   }
 }