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 /* Test pop/shift compiler paths. */

 function a() {

   var x = [];

   for (var i = 0; i < 50; i++)

     x.push(i);

   for (var j = 0; j < 100; j++) {

     var z = x.shift();

     if (j < 50)

       assertEq(z, j);

     else

       assertEq(z, undefined);

   }

 }

 a();

 function b() {

   var x = [];

   for (var i = 0; i < 50; i++)

     x.push(i);

   for (var j = 0; j < 100; j++) {

     var z = x.pop();

     if (j < 50)

       assertEq(z, 49 - j);

     else

       assertEq(z, undefined);

   }

 }

 b();