Description:
------------
This one is somewhat following https://bugs.php.net/bug.php?id=81294 and is again related to the removal of a filter. If the filter being removed outputs additional data then this data is correctly written to the underlying stream however the stream position is not updated.

Seems that this should be done here:
https://github.com/php/php-src/blob/PHP-8.0.8/main/streams/filter.c#L471

Or instead of using 

stream->ops->write(stream, bucket->buf, bucket->buflen);

probably call (speculating) https://github.com/php/php-src/blob/PHP-8.0.8/main/streams/streams.c#L1120

Test script:
---------------
<?
  $f = fopen("php://memory", "wb");
  $z = stream_filter_append($f, "zlib.deflate", STREAM_FILTER_WRITE, 6);
  fwrite($f, "Test");
  stream_filter_remove($z);
  echo "Position after remove: " . ftell($f) . "\n"; // 0 reported, should be 6
  echo "Read: " . strlen(fread($f, 1024)) . "\n"; // 0 bytes
  fseek($f, 0);
  echo "Read after seek to the beginning: " . strlen(fread($f, 1024)) . "\n"; // 6 bytes read, so ftell should have reported 6
  fclose($f);
?>


Expected result:
----------------
After a filter is removed if it outputs additional data the underlying stream position (ftell) should be updated accordingly.