Sysext Modules are shown in Module Menu, even though extensions are not installed
After File -> List was moved into a sysext it was possible to uninstall it.
The problem is that in t3lib/stddb/tables.php (line 444) it makes the file -> list module visible with the following array (not depending on the if the extension is installed or not)
$TBE_MODULES = array(
'web' => 'list,info,perm,func',
'file' => 'list',
'user' => 'ws',
'tools' => 'em',
'help' => 'about,cshmanual'
Clicking the "File list" module returns a blank page.
(issue imported from #M15794)