Enum is treated as a reserved word, even before PHP 8.1 #896
Description
Input: class Enum {}
Output: syntax error, unexpected 'Enum' (T_ENUM), expecting T_STRING
The official PHP parser seems to be able to handle this example even after PHP 8.1 - if that turns out to be too difficult to fix here, maybe should consider adding the keyword only for PHP >= 8.1?
Also see #895 for a failing test.