Return a newly created char-table, with purpose PURPOSE.
Each element is initialized to INIT, which defaults to nil.
PURPOSE should be a symbol. If it has a `char-table-extra-slots'
property, the property's value should be an integer between 0 and 10
that specifies how many extra slots the char-table has. Otherwise,
the char-table has no extra slot.
(fn PURPOSE &optional INIT)