[d8 Workers] Throw when calling Worker constructor without new

test/mjsunit/regress-4399.js

Index: test/mjsunit/regress-4399.js
diff --git a/test/mjsunit/regress/regress-crbug-503698.js b/test/mjsunit/regress-4399.js
similarity index 73%
copy from test/mjsunit/regress/regress-crbug-503698.js
copy to test/mjsunit/regress-4399.js
index 415d1bc81be5ac46fb358ce8ec681b1e5c276e07..a8fdab7d9d62dfa33d34987f8994536e5dc762cc 100644
--- a/test/mjsunit/regress/regress-crbug-503698.js
+++ b/test/mjsunit/regress-4399.js
@@ -2,8 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --invoke-weak-callbacks
 
 if (this.Worker) {
-  var __v_6 = new Worker('');
+  assertThrows(function() { Worker.prototype.constructor("55"); });
 }