Both bits DATA_VERSIONED will be set in prtype if the column
is system-versioned. The bits will be 0 for normal unversioned
columns. For the special columns identifying the logical start
and end times of versions, only one bit will be set:
DATA_VERS_START or DATA_VERS_END.

create_table_info_t::create_table_def(),
prepare_inplace_alter_table_dict(): Set prtype |= DATA_VERSIONED
for system-versioned columns.

dfield_t::is_version_historical_end(): Determine if a data tuple
field is_version_end() and contains a timestamp in the past
(not TRX_ID_MAX).

dtype_t, dict_col_t: Add the accessors
is_versioned(), is_version_start(), is_version_end().

trx_id_max_bytes[]: The bit pattern of TRX_ID_MAX, for use with
memcmp().