Revert "Model 'await for' as an explicit node in tree and fix its handling."

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 ac68fbd45f8249a36219cbe57cbb9cb1ca9fbe2d..4aaa293a517a487019f9f1d0da5edbc01a2695fe 100644
--- a/pkg/compiler/lib/src/closure.dart
+++ b/pkg/compiler/lib/src/closure.dart
@@ -1069,12 +1069,16 @@ class ClosureTranslator extends Visitor {
     inTryStatement = oldInTryStatement;
   }
 
-  visitAsyncForIn(AsyncForIn node) {
-    // An `await for` loop is enclosed in an implicit try-finally.
-    bool oldInTryStatement = inTryStatement;
-    inTryStatement = true;
-    visitLoop(node);
-    inTryStatement = oldInTryStatement;
+  visitForIn(ForIn node) {
+    if (node.awaitToken != null) {
+      // An `await for` loop is enclosed in an implicit try-finally.
+      bool oldInTryStatement = inTryStatement;
+      inTryStatement = true;
+      visitLoop(node);
+      inTryStatement = oldInTryStatement;
+    } else {
+      visitLoop(node);
+    }
   }
 }