Disable map-check relying on cache behavior sensitive to GC-timing

test/mjsunit/track-fields.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 193 matching lines @@
 var o19 = {};
 o19.field1 = 100;
 o19.field2 = 1.6;
 o19.to_delete = 100;
 
 assertFalse(%HaveSameMap(o18, o19));
 
 delete o18.to_delete;
 delete o19.to_delete;
 
-assertTrue(%HaveSameMap(o18, o19));
 assertEquals(1, o18.field2);
 assertEquals(1.6, o19.field2);
 
 // Test megamorphic keyed stub behaviour in combination with representations.
 var some_object20 = {"a":1};
 var o20 = {};
 o20.smi = 1;
 o20.dbl = 1.5;
 o20.obj = some_object20;
 
@@ skipping 173 matching lines @@
   var o = {"s_to_t":18};
   o.s_to_t = a;
   return o;
 }
 
 var st1 = smi_to_object(true);
 var st2 = smi_to_object(false);
 assertTrue(%HaveSameMap(st1, st2));
 assertEquals(true, st1.s_to_t);
 assertEquals(false, st2.s_to_t);