[php-src] Issue #13280: tmpfile() $mode argument

Issue: https://github.com/php/php-src/issues/13280 Author: divinity76 ### Description I want a tmpfile() in a+b mode, quote >In this mode, [fseek()](https://www.php.net/manual/en/function.fseek.php) only affects the >reading position, writes are always appended. I want a tmpfile() where fseek() only affect the reading position, and writes are always appended. I cannot use fopen("php://temp","a+b") because I need the file uri (stream_get_meta_data($fp)['uri']) I wish tmpfile() had a $mode option like: ``` tmpfile(string $mode = "w+b"): resource|false ``` So I could do ``` $fp = tmpfile("a+b"); ```