API Report::get_reports() returns native array (fixes #8096)

Used to return ArrayList, but since 9d74c99 its no
longer using keys, which they functionality using these return
values rely on. Hence the breakage of ReportAdmin,
since no report was being detected as "current" by looking
through the array keys.

code/reports/Report.php

@@ -163,7 +163,7 @@ static public function get_excluded_reports() {
 
 	/**
 	 * Return the SS_Report objects making up the given list.
-	 * @return ArrayList an arraylist of SS_Report objects
+	 * @return Array of SS_Report objects
 	 */
 	static public function get_reports() {
 		$reports = ClassInfo::subclassesFor(get_called_class());
@@ -182,13 +182,12 @@ static public function get_reports() {
 			}
 		}
 
-		//convert array into ArrayList
-		$list = ArrayList::create($reportsArray);
+		uasort($reportsArray, function($a, $b) {
+			if($a->sort == $b->sort) return 0;
+			else return ($a->sort < $b->sort) ? -1 : 1;
+		});
 
-		//sort
-		$list = $list->sort('sort');
-
-		return $list;
+		return $reportsArray;
 	}
 
 	/////////////////////// UI METHODS ///////////////////////