Reassignment of $this is not an error

[luauser32167]

No error is reported for:

$this = 1;

But php -l reports Fatal error: Cannot re-assign $this...

[staabm]

another repro
https://phpstan.org/r/28b4faa1-edb4-4790-89d7-9c17b181943b
https://3v4l.org/gSRUE#veol