When creating an index containing a too long record, InnoDB would
dereference a NULL pointer when trying to determine the maximum row length.

innodb_check_for_record_too_big_error(): Replace the dict_table_t*
parameter with a Boolean flag.  There is not always a dict_table_t object
when this function is called.

page_get_free_space_of_empty_noninline(): Move the definition and
declaration from row0mysql (!) to page0page.  Make the signature
identical with page_get_free_space_of_empty().

create_clustered_index_when_no_primary(): Add the parameter "comp".
Remove unnecessary casts.