Add a create_wp_error action which is called when a WP_Error instance is created. Fixes #28319. Props ebinnion

git-svn-id: https://develop.svn.wordpress.org/trunk@29033 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-error.php

@@ -63,6 +63,15 @@ class WP_Error {
 
 		if ( ! empty($data) )
 			$this->error_data[$code] = $data;
+
+		/**
+		 * Fires when a WP_Error object instance is created.
+		 *
+		 * @since 4.0.0
+		 *
+		 * @param WP_Error $this The WP_Error instance.
+		 */
+		do_action( 'create_wp_error', $this );
 	}
 
 	/**