The assumption is that the engine should not need to
evaluate HAVING on the table->record[0] - the engine either
can evaluate HAVING internally before writing it to the
table->record[0], or it should leave it to the server,
that will evaluate HAVING(table->record[0]).

Similarly the engine should not need to evaluate ORDER
on the table->record[0]. Either it returns the data already
sorted, or the server will sort the table.