Add missing access modifiers to methods/members in `WP_Image_Editor_*` classes.

See #27881, #22234.

Built from https://develop.svn.wordpress.org/trunk@28513


git-svn-id: http://core.svn.wordpress.org/trunk@28339 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-image-editor-gd.php

@@ -18,7 +18,7 @@ class WP_Image_Editor_GD extends WP_Image_Editor {
 
 	protected $image = false; // GD Resource
 
-	function __destruct() {
+	public function __destruct() {
 		if ( $this->image ) {
 			// we don't need the original in memory anymore
 			imagedestroy( $this->image );

wp-includes/class-wp-image-editor-imagick.php

@@ -18,7 +18,7 @@ class WP_Image_Editor_Imagick extends WP_Image_Editor {
 
 	protected $image = null; // Imagick Object
 
-	function __destruct() {
+	public function __destruct() {
 		if ( $this->image instanceof Imagick ) {
 			// we don't need the original in memory anymore
 			$this->image->clear();