Remove runtime flags for Proxy and Reflect

test/mjsunit/regress/regress-crbug-505907.js

Index: test/mjsunit/regress/regress-crbug-505907.js
diff --git a/test/mjsunit/regress/regress-crbug-505907.js b/test/mjsunit/regress/regress-crbug-505907.js
index c8d4bac9be5249af547ea3fcf58b8ef3cf8612ca..ec7b80baa83a3cceee2dc94ef2929da27810c9a5 100644
--- a/test/mjsunit/regress/regress-crbug-505907.js
+++ b/test/mjsunit/regress/regress-crbug-505907.js
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-proxies
-
 try {
   var p = new Proxy({}, {
       getPropertyDescriptor: function() { return [] }