Remove runtime flags for Proxy and Reflect

test/mjsunit/harmony/proxies-accesschecks.js

Index: test/mjsunit/harmony/proxies-accesschecks.js
diff --git a/test/mjsunit/harmony/proxies-accesschecks.js b/test/mjsunit/harmony/proxies-accesschecks.js
deleted file mode 100644
index 209d4329f956f50464947aa4c3e59d189e66ca9c..0000000000000000000000000000000000000000
--- a/test/mjsunit/harmony/proxies-accesschecks.js
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --harmony-proxies
-
-var realm = Realm.create();
-
-this.__proto__ = new Proxy({}, {
-  getPrototypeOf() { assertUnreachable() },
-  get() { assertUnreachable() }
-});
-
-var other_type_error = Realm.eval(realm, "TypeError");
-assertThrows(() => Realm.eval(realm, "Realm.global(0).foo"), other_type_error);