Implement symbol @@hasInstance for ES6 instanceof support.

test/mjsunit/random-bit-correlations.js

 // 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: --random-seed=12 --nostress-opt --noalways-opt --predictable
+// Flags: --random-seed=20 --nostress-opt --noalways-opt --predictable
 
 (function() {
   var kHistory = 2;
   var kRepeats = 100;
   var history = new Uint32Array(kHistory);
 
   function random() {
     return (Math.random() * Math.pow(2, 32)) >>> 0;
   }
 
@@ skipping 44 matching lines @@
         // For 1 degree of freedom this corresponds to 1 in a million.  We are
         // running ~8000 tests, so that would be surprising.
         assertTrue(chi_squared <= 24);
         // If the predictor bit is a fixed 0 or 1 then it makes no sense to
         // repeat the test with a different age.
         if (predictor_bit < 0) break;
       }
     }
   }
 })();