Load: move `is_wp_error()` to `load.php` so that `WP_Error` is in a file by itself.

See #37827.

Built from https://develop.svn.wordpress.org/trunk@38363


git-svn-id: http://core.svn.wordpress.org/trunk@38304 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-error.php

@@ -202,17 +202,3 @@ class WP_Error {
 		unset( $this->error_data[ $code ] );
 	}
 }
-
-/**
- * Check whether variable is a WordPress Error.
- *
- * Returns true if $thing is an object of the WP_Error class.
- *
- * @since 2.1.0
- *
- * @param mixed $thing Check if unknown variable is a WP_Error object.
- * @return bool True, if WP_Error. False, if not WP_Error.
- */
-function is_wp_error( $thing ) {
-	return ( $thing instanceof WP_Error );
-}

wp-includes/load.php

@@ -1045,3 +1045,17 @@ function wp_doing_ajax() {
 	 */
 	return apply_filters( 'wp_doing_ajax', defined( 'DOING_AJAX' ) && DOING_AJAX );
 }
+
+/**
+ * Check whether variable is a WordPress Error.
+ *
+ * Returns true if $thing is an object of the WP_Error class.
+ *
+ * @since 2.1.0
+ *
+ * @param mixed $thing Check if unknown variable is a WP_Error object.
+ * @return bool True, if WP_Error. False, if not WP_Error.
+ */
+function is_wp_error( $thing ) {
+	return ( $thing instanceof WP_Error );
+}

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7-alpha-38362';
+$wp_version = '4.7-alpha-38363';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.