Initializing a table doesn't satisfied `need-check-nil`

Issue Description

Hi!

I have a code that looks something like this:

---@param t? table
function api.f(t)
	t = type(t) == "table" and t or {}
	t.x = t.x or {} --warning is raised but t can never be nil here because it is set to {} if it was but diagnostics fail to see that
	--etc.
end

Nil checks are not required here because t should never be nil, the preceding lines redefines it as an empty table if it was nil or invalid so the reference should always exist when trying to check if x exists within the table.

I have seen similar reports but I'm not sure if this exact case has been reported or not. I couldn't find a match or I failed to recognize it.

Additional Notes

No response

Aucun fichier source ni test n’est indiqué. Commencez par reproduire l’exemple Lua et suivre le diagnostic de vérification de nil pour l’avertissement need-check-nil ; le travail est terminé lorsque l’avertissement n’est pas signalé pour t.x après la normalisation de t en table.