PHP 8.0 | PHP/NoSilencedErrors: review function list

PHP 8 changes the behaviour of the error silence operator @ : where previously it would silence all notices, warnings and errors, it will now only silence notices and warnings, but will not prevent fatal errors/catchable exceptions anymore.

PHP 8 also contains another relevant change, which is that the error level for a number of notices/warnings has been elevated to fatal error/catchable exception.

It would be very helpful if someone would review if any of the functions in the $function_whitelist are affected by these changes and need to be removed from the list.

Note: yes, the name of the property should also be changed, but there's a separate open ticket for that.

This was also discussed in the #core-php Slack channel: https://wordpress.slack.com/archives/C60K3MP2Q/p1611678080004700

Start by locating the PHP/NoSilencedErrors implementation and its $function_whitelist. Review each listed function against the PHP 8 error-silencing and error-level changes described in the issue, then update the list where needed and run the relevant project checks to confirm the sniff remains correct.