Remove XEmacs compat code from table.el

Remove XEmacs compat code from table.el

* lisp/textmodes/table.el:
(table-disable-menu, null, table-recognize-cell)
(table--make-cell-map, table--update-cell)
(table--update-cell-widened, table--update-cell-heightened)
(table--read-from-minibuffer, table--untabify)
(table--update-cell-face, table--warn-incompatibility)
(table--fill-region, table--set-timer): Remove XEmacs compat code.