Migrate the error handling for the @ operator to php 8 state

[chris-doehring]

While trying to execute the unit tests of the latest state of the php8-support branch locally, I was able to find the reason why the error_handler_respects_error_reporting.phpt test keeps failing. The reason is mentioned in the official php 8 migration guide:

The @ operator will no longer silence fatal errors (E_ERROR, E_CORE_ERROR, E_COMPILE_ERROR, E_USER_ERROR, E_RECOVERABLE_ERROR, E_PARSE). Error handlers that expect error_reporting to be 0 when @ is used, should be adjusted to use a mask check instead:

<?php
// Replace
function my_error_handler($err_no, $err_msg, $filename, $linenum) {
    if (error_reporting() == 0) {
        return; // Silenced
    }
    // ...
}

// With
function my_error_handler($err_no, $err_msg, $filename, $linenum) {
    if (!(error_reporting() & $err_no)) {
        return; // Silenced
    }
    // ...
}
?>

You will see that the error_reporting under php 8 no longer returns 0 (none) within a custom error handler: https://3v4l.org/qZ1OG

After this change, my local tests run successful under php 7.2 - 8.0. This does not fix the Segmentation faults or the other remaining CI issues.

[ste93cry]

Can you please add a CHANGELOG entry?

[ste93cry]

Thank you for your help, LGTM