Fix for 'await' highlighting in for-each.

pkg/analysis_server/test/analysis/notification_highlights_test.dart

Index: pkg/analysis_server/test/analysis/notification_highlights_test.dart
diff --git a/pkg/analysis_server/test/analysis/notification_highlights_test.dart b/pkg/analysis_server/test/analysis/notification_highlights_test.dart
index a12add97ae529aacf41f1dfbb45ff3f58d89de5b..89c8af1661844e4f3166bbe83941be6bed07c2b3 100644
--- a/pkg/analysis_server/test/analysis/notification_highlights_test.dart
+++ b/pkg/analysis_server/test/analysis/notification_highlights_test.dart
@@ -180,10 +180,14 @@ main() {
     addTestFile('''
 main() async {
   await 42;
+  await for (var item in []) {
+    print(item);
+  }
 }
 ''');
     return prepareHighlights().then((_) {
       assertHasRegion(HighlightRegionType.BUILT_IN, 'await 42');
+      assertHasRegion(HighlightRegionType.BUILT_IN, 'await for');
     });
   }