[php] Add the `http_response_code()` function (#9683)

* [php] Add the `http_response_code()` function

* [php] Fixed the `http_response_code()` signature

std/php/Global.hx

@@ -1489,4 +1489,9 @@ extern class Global {
 		@see http://php.net/manual/en/function.cli-set-process-title.php
 	**/
 	static function cli_set_process_title(title:String):Bool;
+
+	/**
+		@see http://php.net/manual/en/function.http-response-code.php
+	**/
+	static function http_response_code(?response_code:Int):EitherType<Int, Bool>;
 }