of clustered indexes. Previously, parts of the code assumed that these
columns would exist on all leaf pages. Simplify the update-in-place of
these columns.
Add inline function dict_index_is_clust() to replace all tests
index->type & DICT_CLUSTERED.
Remove the redo log entry types MLOG_ZIP_WRITE_TRX_ID and
MLOG_ZIP_WRITE_ROLL_PTR, because the modifications to these columns
are covered by logical logging.
Fuse page_zip_write_trx_id() and page_zip_write_roll_ptr() into
page_zip_write_trx_id_and_roll_ptr().
page_zip_dir_add_slot(), page_zip_available(): Add flag "is_clustered",
so that no space will be reserved for TRX_ID and ROLL_PTR on leaf pages
of secondary indexes.
page_zip_apply_log(): Flag an error when val==0 is encoded with two bytes.
page_zip_write_rec(): Add debug assertions that there is enough space
available for the entry before copying the data bytes of the record.
that will require complete index information.
dict_create_index_step(): invoke dict_index_add_to_cache() before btr_create()
dict_index_remove_from_cache(): make public
dict_index_get_if_in_cache_low(): new function, for holding dict_sys->mutex
buf_flush_init_for_writing(): remove the temporary hook to page_zip_compress()
page_create(): add temporary hook to page_zip_compress()
