Use goog.array.extend instead of ol.array.safeExtend

The upstream implementation now supports large arrays.
See https://github.com/google/closure-library/pull/356

src/ol/array.js

@@ -37,25 +37,6 @@ ol.array.binaryFindNearest = function(arr, target) {
 };
 
 
-/**
- * Safe version of goog.array.extend that does not risk to overflow the stack
- * even if `array2` contains a large number of elements.
- *
- * @param {Array.<T>} array1 Array 1.
- * @param {Array.<T>} array2 Array 2.
- * @template T
- */
-ol.array.safeExtend = function(array1, array2) {
-  // goog.array.extend uses Array.prototype.push.apply, which can overflow the
-  // stack if array2 contains too many elements.  Repeatedly calling push
-  // performs as well on modern browsers.
-  var i, ii;
-  for (i = 0, ii = array2.length; i < ii; ++i) {
-    array1.push(array2[i]);
-  }
-};
-
-
 /**
  * @param {Array.<number>} arr Array.
  * @param {number} target Target.