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

pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart

Index: pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart
diff --git a/pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart b/pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart
index c169871146c2caef1fb9a42b000665db370857a1..d740569c0a627a7605798dad2a13243c4e753dab 100644
--- a/pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart
+++ b/pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart
@@ -1329,12 +1329,18 @@ class SimpleTypeInferrerVisitor<T>
     return null;
   }
 
-  T handleForInLoop(ast.ForIn node, T iteratorType, Selector currentSelector,
-                    Selector moveNextSelector) {
-    handleDynamicSend(node, moveNextSelector, iteratorType,
-                      new ArgumentsTypes<T>.empty());
-    T currentType = handleDynamicSend(node, currentSelector, iteratorType,
-                                      new ArgumentsTypes<T>.empty());
+  T visitForIn(ast.ForIn node) {
+    T expressionType = visit(node.expression);
+    Selector iteratorSelector = elements.getIteratorSelector(node);
+    Selector currentSelector = elements.getCurrentSelector(node);
+    Selector moveNextSelector = elements.getMoveNextSelector(node);
+
+    T iteratorType =
+        handleDynamicSend(node, iteratorSelector, expressionType, null);
+    handleDynamicSend(node, moveNextSelector,
+                      iteratorType, new ArgumentsTypes<T>([], null));
+    T currentType =
+        handleDynamicSend(node, currentSelector, iteratorType, null);
 
     if (node.expression.isThis()) {
       // Any reasonable implementation of an iterator would expose
@@ -1360,35 +1366,4 @@ class SimpleTypeInferrerVisitor<T>
       visit(node.body);
     });
   }
-
-  T visitAsyncForIn(ast.AsyncForIn node) {
-    T expressionType = visit(node.expression);
-
-    Selector currentSelector = elements.getCurrentSelector(node);
-    Selector moveNextSelector = elements.getMoveNextSelector(node);
-
-    js.JavaScriptBackend backend = compiler.backend;
-    Element ctor = backend.getStreamIteratorConstructor();
-
-    /// Synthesize a call to the [StreamIterator] constructor.
-    T iteratorType = handleStaticSend(null, null, ctor,
-                                      new ArgumentsTypes<T>([expressionType],
-                                                            null));
-
-    return handleForInLoop(node, iteratorType, currentSelector,
-                           moveNextSelector);
-  }
-
-  T visitSyncForIn(ast.SyncForIn node) {
-    T expressionType = visit(node.expression);
-    Selector iteratorSelector = elements.getIteratorSelector(node);
-    Selector currentSelector = elements.getCurrentSelector(node);
-    Selector moveNextSelector = elements.getMoveNextSelector(node);
-
-    T iteratorType = handleDynamicSend(node, iteratorSelector, expressionType,
-                                       new ArgumentsTypes<T>.empty());
-
-    return handleForInLoop(node, iteratorType, currentSelector,
-                           moveNextSelector);
-  }
 }