[php] Add externs for `random_bytes()` and `random_int()` (#9884)

std/php/Global.hx

@@ -554,6 +554,16 @@ extern class Global {
 	**/
 	static function mt_getrandmax():Int;
 
+	/**
+		@see http://php.net/manual/en/function.random-bytes.php
+	**/
+	static function random_bytes(length:Int):String;
+
+	/**
+		@see http://php.net/manual/en/function.random-int.php
+	**/
+	static function random_int(min:Int, max:Int):Int;
+
 	/**
 		@see http://php.net/manual/en/function.is-nan.php
 	**/