remove ClosureWrap option and related implementation

test/checker/inferred_type_test.dart

Index: test/checker/inferred_type_test.dart
diff --git a/test/checker/inferred_type_test.dart b/test/checker/inferred_type_test.dart
index 3a0cccc47de760c7ab11a0284e0ea5242c2c24a1..be7a158a837ad143c6ccbe10c00a720cb45309ee 100644
--- a/test/checker/inferred_type_test.dart
+++ b/test/checker/inferred_type_test.dart
@@ -1513,6 +1513,6 @@ void main() {
         }
       }
       '''
-    }, inferDownwards: true, wrapClosures: false);
+    }, inferDownwards: true);
   });
 }