GitLab

rec_get_converted_size_comp(): Replace status,fields,n_fields with tuple.

rec_init_offsets_comp_ordinary(), rec_get_converted_size_comp_prefix_low(),
rec_convert_dtuple_to_rec_comp(): Add template<bool mblob = false>.
With mblob=true, process a record with a metadata BLOB.

rec_copy_prefix_to_buf(): Assert that no fields beyond the key and
system columns are being copied. Exclude the metadata BLOB field.