[php-src] Issue #10516: pack for an array of values

Issue: https://github.com/php/php-src/issues/10516 Author: GajowyJ ### Description pack() function takes as arguments: format and then list of values. pack(string $format, mixed ...$values): string Quite ofthen an array of data need to be packed and there is no function to do it efficiently. Let say we have a table with a number (milions or more) of double values. A code like this needs to be used: ``` $data=''; foreach( $array as $double ) $data .= pack('d',$double); ``` It would be usefull if one could execute instead: $data = vpack('d*',$array);