Ensure newly allocated empty Arrays are transitioned to FAST_ELEMENT

test/mjsunit/array-literal-transitions.js

 // Copyright 2011 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 27 matching lines @@
 if (support_smi_only_arrays) {
   print("Tests include smi-only arrays.");
 } else {
   print("Tests do NOT include smi-only arrays.");
 }
 
 // IC and Crankshaft support for smi-only elements in dynamic array literals.
 function get(foo) { return foo; }  // Used to generate dynamic values.
 
 function array_literal_test() {
+  var c0 = [1, 2, get(3.5)];
+  assertTrue(%HasFastDoubleElements(c0));
+  assertEquals(3.5, c0[2]);
+  assertEquals(2, c0[1]);
+  assertEquals(1, c0[0]);
+
   var a0 = [1, 2, 3];
   assertTrue(%HasFastSmiOnlyElements(a0));
   var a1 = [get(1), get(2), get(3)];
   assertTrue(%HasFastSmiOnlyElements(a1));
 
   var b0 = [1, 2, get("three")];
   assertTrue(%HasFastElements(b0));
   var b1 = [get(1), get(2), get("three")];
   assertTrue(%HasFastElements(b1));
 
-  var c0 = [1, 2, get(3.5)];
-  assertTrue(%HasFastDoubleElements(c0));
-  assertEquals(3.5, c0[2]);
-  assertEquals(2, c0[1]);
-  assertEquals(1, c0[0]);
-
   var c1 = [1, 2, 3.5];
   assertTrue(%HasFastDoubleElements(c1));
   assertEquals(3.5, c1[2]);
   assertEquals(2, c1[1]);
   assertEquals(1, c1[0]);
 
   var c2 = [get(1), get(2), get(3.5)];
   assertTrue(%HasFastDoubleElements(c2));
   assertEquals(3.5, c2[2]);
   assertEquals(2, c2[1]);
@@ skipping 127 matching lines @@
   assertEquals(1, array[1]);
   assertEquals(foo, array[2]);
 }
 
 (function literals_after_osr() {
   var color = [0];
   // Trigger OSR.
   while (%GetOptimizationStatus(literals_after_osr) == 2) {}
   return [color[0]];
 })();