Optimistically assume that elements IC only transition once.

test/mjsunit/elements-kind.js

 // Copyright 2012 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 206 matching lines @@
     assertEquals(value, array[1]);
   }
   smis = construct_smis();
   for (var i = 0; i < 3; i++) {
     convert_mixed(smis, 1.5, elements_kind.fast_double);
   }
   doubles = construct_doubles();
   for (var i = 0; i < 3; i++) {
     convert_mixed(doubles, "three", elements_kind.fast);
   }
+  convert_mixed(construct_smis(), "three", elements_kind.fast);
+  convert_mixed(construct_doubles(), "three", elements_kind.fast);
+  %OptimizeFunctionOnNextCall(convert_mixed);
   smis = construct_smis();
   doubles = construct_doubles();
-  %OptimizeFunctionOnNextCall(convert_mixed);
   convert_mixed(smis, 1, elements_kind.fast);
   convert_mixed(doubles, 1, elements_kind.fast);
   assertTrue(%HaveSameMap(smis, doubles));
 }
 
 // Crankshaft support for smi-only elements in dynamic array literals.
 function get(foo) { return foo; }  // Used to generate dynamic values.
 
 function crankshaft_test() {
   if (support_smi_only_arrays) {
@@ skipping 97 matching lines @@
   var a = ["foo", "bar"];
   assertKind(elements_kind.fast, a);
   var b = a.splice(0, 1);
   assertKind(elements_kind.fast, b);
   var c = a.slice(0, 1);
   assertKind(elements_kind.fast, c);
 }
 
 // Throw away type information in the ICs for next stress run.
 gc();