Remove runtime flags for Proxy and Reflect

test/mjsunit/harmony/exponentiation-operator.js

 // Copyright 2016 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-exponentiation-operator --harmony-proxies
+// Flags: --harmony-exponentiation-operator
 
 function TestBasic() {
   assertEquals(-(8 ** 2), -64);
   assertEquals(+(8 ** 2), 64);
   assertEquals(~(8 ** 2), -65);
   assertEquals(!(8 ** 2), false);
 
   assertEquals(2 ** -2, 0.25);
 
   var o = { p: 1 };
@@ skipping 253 matching lines @@
   assertThrows("if (false) { 17 **= 10; }", ReferenceError);
   assertThrows("if (false) { '17' **= 10; }", ReferenceError);
   assertThrows("if (false) { /17/ **= 10; }", ReferenceError);
   assertThrows("if (false) { ({ valueOf() { return 17; } } **= 10); }",
                ReferenceError);
   // TODO(caitp): a Call expression as LHS should be an early ReferenceError!
   // assertThrows("if (false) { Array() **= 10; }", ReferenceError);
   assertThrows(() => Array() **= 10, ReferenceError);
 }
 TestBadAssignmentLHS();