…43738)

Problem Summary:
before in the pull function, it's use tmp_block to reference data and
swap with output_block.
and then create empty column in join_block, so insert into data at next
time, it's need malloc memory again.

after fixed:
```
mysql [ssb]>set parallel_pipeline_task_num = 0;
mysql [ssb]>select count(c_custkey) from (select c_custkey from customer cross join dates)t;
+------------------+
| count(c_custkey) |
+------------------+
|       7668000000 |
+------------------+
1 row in set (0.32 sec)

mysql [ssb]>set parallel_pipeline_task_num = 1;
Query OK, 0 rows affected (0.00 sec)

mysql [ssb]>select count(c_custkey) from (select c_custkey from customer cross join dates)t;
+------------------+
| count(c_custkey) |
+------------------+
|       7668000000 |
+------------------+
1 row in set (5.61 sec)
```

before
```
mysql [ssb]>set parallel_pipeline_task_num = 0;
Query OK, 0 rows affected (0.00 sec)

mysql [ssb]>select count(c_custkey) from (select c_custkey from customer cross join dates)t;
+------------------+
| count(c_custkey) |
+------------------+
|       7668000000 |
+------------------+
1 row in set (2.79 sec)

mysql [ssb]>set parallel_pipeline_task_num = 1;
Query OK, 0 rows affected (0.00 sec)

mysql [ssb]>select count(c_custkey) from (select c_custkey from customer cross join dates)t;
+------------------+
| count(c_custkey) |
+------------------+
|       7668000000 |
+------------------+
1 row in set (10.21 sec)
```