Introduce __return_empty_array() and use it instead of create_function in the theme preview.

git-svn-id: https://develop.svn.wordpress.org/trunk@14641 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/functions.php

@@ -4162,6 +4162,19 @@ function __return_zero() {
 	return 0;
 }
 
+/**
+ * Returns an empty array
+ *
+ * Useful for returning an empty array to filters easily
+ *
+ * @since 3.0.0
+ * @see __return_zero()
+ * @return array Empty array
+ */
+function __return_empty_array() {
+	return array();
+}
+
 /**
  * Send a HTTP header to disable content type sniffing in browsers which support it.
  *