Remove indexOfNaN in favor of baseFindIndex.

lodash.js

@@ -721,7 +721,7 @@
    */
   function baseIndexOf(array, value, fromIndex) {
     if (value !== value) {
-      return indexOfNaN(array, fromIndex);
+      return baseFindIndex(array, baseIsNaN, fromIndex);
     }
     var index = fromIndex - 1,
         length = array.length;
@@ -756,6 +756,17 @@
     return -1;
   }
 
+  /**
+   * The base implementation of `_.isNaN` without support for number objects.
+   *
+   * @private
+   * @param {*} value The value to check.
+   * @returns {boolean} Returns `true` if `value` is `NaN`, else `false`.
+   */
+  function baseIsNaN(value) {
+    return value !== value;
+  }
+
   /**
    * The base implementation of `_.mean` and `_.meanBy` without support for
    * iteratee shorthands.
@@ -1019,28 +1030,6 @@
     return object == null ? undefined : object[key];
   }
 
-  /**
-   * Gets the index at which the first occurrence of `NaN` is found in `array`.
-   *
-   * @private
-   * @param {Array} array The array to search.
-   * @param {number} fromIndex The index to search from.
-   * @param {boolean} [fromRight] Specify iterating from right to left.
-   * @returns {number} Returns the index of the matched `NaN`, else `-1`.
-   */
-  function indexOfNaN(array, fromIndex, fromRight) {
-    var length = array.length,
-        index = fromIndex + (fromRight ? 1 : -1);
-
-    while ((fromRight ? index-- : ++index < length)) {
-      var other = array[index];
-      if (other !== other) {
-        return index;
-      }
-    }
-    return -1;
-  }
-
   /**
    * Checks if `value` is a host object in IE < 9.
    *
@@ -6919,7 +6908,7 @@
         ) + 1;
       }
       if (value !== value) {
-        return indexOfNaN(array, index - 1, true);
+        return baseFindIndex(array, baseIsNaN, index - 1, true);
       }
       while (index--) {
         if (array[index] === value) {