Move isIndex into runInContext.

lodash.src.js

@@ -515,20 +515,6 @@
     };
   }());
 
-  /**
-   * Checks if `value` is a valid array-like index.
-   *
-   * @private
-   * @param {*} value The value to check.
-   * @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
-   * @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
-   */
-  function isIndex(value, length) {
-    value = +value;
-    length = length == null ? MAX_SAFE_INTEGER : length;
-    return value > -1 && value % 1 == 0 && value < length;
-  }
-
   /**
    * Checks if `value` is object-like.
    *
@@ -3733,6 +3719,20 @@
       return result;
     }
 
+    /**
+     * Checks if `value` is a valid array-like index.
+     *
+     * @private
+     * @param {*} value The value to check.
+     * @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
+     * @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
+     */
+    function isIndex(value, length) {
+      value = +value;
+      length = length == null ? MAX_SAFE_INTEGER : length;
+      return value > -1 && value % 1 == 0 && value < length;
+    }
+
     /**
      * Checks if the provided arguments are from an iteratee call.
      *