With innodb_default_row_format=redundant, InnoDB would crash when
using table options that are incompatible with ROW_FORMAT=REDUNDANT.

create_table_info_t::m_default_row_format: Cache the value of
innodb_default_row_format.

create_table_info_t::check_table_options(): Validate ROW_TYPE_DEFAULT
with m_default_row_format.

create_table_info_t::innobase_table_flags(): Use the
cached m_default_row_format.

create_table_info_t: Never read m_form->s->row_type.
Use m_create_info->row_type instead.

dict_tf_set(): Never set invalid flags for ROW_FORMAT=REDUNDANT.

ha_innobase::truncate(): Set info.row_type based on the ROW_FORMAT
of the current table.