revert mostly to 7.5.0 version of Singleton

#650
#651

CHANGES.md

@@ -4,7 +4,6 @@
 * refactored setting of contributor data for [r42631](https://core.trac.wordpress.org/changeset/42631)
 * refactored `ghu-install.js` to vanilla JavaScript
 * moved GitLab specific admin notices to `GitLab_API`
-* fixed `debug_backtrace()` in `Singleton` to decrease memory footprint
 
 #### 7.5.0 / 2018-01-28
 * fixed _View detail_ ratings for large projects with lots of issues

github-updater.php

@@ -12,7 +12,7 @@
  * Plugin Name:       GitHub Updater
  * Plugin URI:        https://github.com/afragen/github-updater
  * Description:       A plugin to automatically update GitHub, Bitbucket, or GitLab hosted plugins, themes, and language packs. It also allows for remote installation of plugins or themes into WordPress.
- * Version:           7.5.0.8
+ * Version:           7.5.0.9
  * Author:            Andy Fragen
  * License:           GNU General Public License v2
  * License URI:       http://www.gnu.org/licenses/gpl-2.0.html

src/Singleton.php

@@ -36,11 +36,13 @@ final class Singleton {
 		 */
 		public static function get_instance( $class_name, $options = null ) {
 			static $instance = null;
+
 			// TODO shorten syntax for PHP 5.4
-			$backtrace = debug_backtrace( DEBUG_BACKTRACE_IGNORE_ARGS );
+			$backtrace = debug_backtrace();
 			$backtrace = $backtrace[1];
 			$class     = isset( $backtrace['class'] ) ? $backtrace['class'] : null;
 			$class     = self::get_class( $class_name, $class );
+
 			if ( null === $instance || ! isset( $instance[ $class ] ) ) {
 				$instance[ $class ] = new $class( $options );
 			}