Hash join is best not to scan probe-side table when build-side table is empty

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)

```
mysql> create table a(id int);
mysql> create table b(id int);
mysql> insert into b values ... 32768 rows
mysql> explain analyze select * from a,b where a.id=b.id;
+------------------------------+----------+---------+-----------+---------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------+-----------+---------+
| id | estRows | actRows | task | access object | execution info | operator info | memory | disk |
+------------------------------+----------+---------+-----------+---------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------+-----------+---------+
| HashJoin_9 | 40960.00 | 0 | root | | time:38ms, loops:1, build_hash_table:{total:915.2μs, fetch:915.2μs, build:0s} | inner join, equal:[eq(test.a.id, test.b.id)] | 0 Bytes | 0 Bytes |
| ├─TableReader_12(Build) | 9990.00 | 0 | root | | time:827.5μs, loops:1, cop_task: {num: 1, max: 1.02ms, proc_keys: 0, rpc_num: 1, rpc_time: 958.9μs, copr_cache_hit_ratio: 0.00, distsql_concurrency: 15} | data:Selection_11 | 253 Bytes | N/A |
| │ └─Selection_11 | 9990.00 | 0 | cop[tikv] | | tikv_task:{time:0s, loops:1}, scan_detail: {total_keys: 1, get_snapshot_time: 47.2μs, rocksdb: {block: {}}} | not(isnull(test.a.id)) | N/A | N/A |
| │ └─TableFullScan_10 | 10000.00 | 0 | cop[tikv] | table:a | tikv_task:{time:0s, loops:1} | keep order:false, stats:pseudo | N/A | N/A |
| └─TableReader_15(Probe) | 32768.00 | 1024 | root | | time:37.7ms, loops:1, cop_task: {num: 3, max: 12.8ms, min: 12.3ms, avg: 12.5ms, p95: 12.8ms, max_proc_keys: 992, p95_proc_keys: 992, tot_proc: 34ms, rpc_num: 3, rpc_time: 37.5ms, copr_cache_hit_ratio: 0.00, distsql_concurrency: 15} | data:Selection_14 | 11.9 KB | N/A |
| └─Selection_14 | 32768.00 | 1696 | cop[tikv] | | tikv_task:{proc max:12ms, min:12ms, avg: 12ms, p80:12ms, p95:12ms, iters:12, tasks:3}, scan_detail: {total_process_keys: 1696, total_process_keys_size: 62752, total_keys: 1699, get_snapshot_time: 112.1μs, rocksdb: {delete_skipped_count: 95232, key_skipped_count: 96928, block: {}}} | not(isnull(test.b.id)) | N/A | N/A |
| └─TableFullScan_13 | 32768.00 | 1696 | cop[tikv] | table:b | tikv_task:{proc max:12ms, min:12ms, avg: 12ms, p80:12ms, p95:12ms, iters:12, tasks:3} | keep order:false | N/A | N/A |
+------------------------------+----------+---------+-----------+---------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------+-----------+---------+
7 rows in set (0.04 sec)

mysql> alter table b set tiflash replica 1;
mysql> explain analyze select * from a,b where a.id=b.id;
+------------------------------+----------+---------+--------------+---------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------+-----------+---------+
| id | estRows | actRows | task | access object | execution info | operator info | memory | disk |
+------------------------------+----------+---------+--------------+---------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------+-----------+---------+
| HashJoin_9 | 40960.00 | 0 | root | | time:66.5ms, loops:1, build_hash_table:{total:1.2ms, fetch:1.2ms, build:0s} | inner join, equal:[eq(test.a.id, test.b.id)] | 0 Bytes | 0 Bytes |
| ├─TableReader_12(Build) | 9990.00 | 0 | root | | time:1.12ms, loops:1, cop_task: {num: 1, max: 1.32ms, proc_keys: 0, rpc_num: 1, rpc_time: 1.24ms, copr_cache_hit_ratio: 0.00, distsql_concurrency: 15} | data:Selection_11 | 261 Bytes | N/A |
| │ └─Selection_11 | 9990.00 | 0 | cop[tikv] | | tikv_task:{time:0s, loops:1}, scan_detail: {total_keys: 1, get_snapshot_time: 170.8μs, rocksdb: {block: {}}} | not(isnull(test.a.id)) | N/A | N/A |
| │ └─TableFullScan_10 | 10000.00 | 0 | cop[tikv] | table:a | tikv_task:{time:0s, loops:1} | keep order:false, stats:pseudo | N/A | N/A |
| └─TableReader_18(Probe) | 32768.00 | 1024 | root | | time:66.2ms, loops:1, cop_task: {num: 1, max: 61.5ms, proc_keys: 0, rpc_num: 1, rpc_time: 61.5ms, copr_cache_hit_ratio: 0.00, distsql_concurrency: 15} | data:Selection_17 | 256.7 KB | N/A |
| └─Selection_17 | 32768.00 | 32768 | cop[tiflash] | | tiflash_task:{time:13.3ms, loops:1, threads:1} | not(isnull(test.b.id)) | N/A | N/A |
| └─TableFullScan_16 | 32768.00 | 32768 | cop[tiflash] | table:b | tiflash_task:{time:12.3ms, loops:1, threads:1}, tiflash_scan:{dtfile:{total_scanned_packs:4, total_skipped_packs:0, total_scanned_rows:32768, total_skipped_rows:0, total_rs_index_load_time: 0ms, total_read_time: 1ms}, total_create_snapshot_time: 0ms} | keep order:false | N/A | N/A |
+------------------------------+----------+---------+--------------+---------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------+-----------+---------+
7 rows in set (0.07 sec)
```

### 2. What did you expect to see? (Required)

The table scan is not executed on probe side, just like mysql or oracle, e.g. mysql execution plan:
```
mysql> explain analyze select /*+ hash_join(b,a) */ * from a,b where a.id=b.id;
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| EXPLAIN |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| -> Inner hash join (b.id = a.id) (cost=3301.40 rows=3277) (actual time=0.029..0.029 rows=0 loops=1)
-> Table scan on b (cost=351.93 rows=32768) (never executed)
-> Hash
-> Table scan on a (cost=0.35 rows=1) (actual time=0.023..0.023 rows=0 loops=1)
|
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
```

### 3. What did you see instead (Required)

The probe side actually performs the table scan, resulting in unnecessary overhead.

### 4. What is your TiDB version? (Required)

master