### What changes were proposed in this pull request?
The original [JIRA Hive-1642](https://issues.apache.org/jira/browse/HIVE-1642) delivered the test cases `auto_joinXYZ` for verifying the results when the joins are automatically converted to map-join. Basically, most of them are just copied from the corresponding `joinXYZ`.

After comparison between `auto_joinXYZ` and `joinXYZ`, below is a list of duplicate cases:
```
    "auto_join0",
    "auto_join1",
    "auto_join10",
    "auto_join11",
    "auto_join12",
    "auto_join13",
    "auto_join14",
    "auto_join14_hadoop20",
    "auto_join15",
    "auto_join17",
    "auto_join18",
    "auto_join2",
    "auto_join20",
    "auto_join21",
    "auto_join23",
    "auto_join24",
    "auto_join3",
    "auto_join4",
    "auto_join5",
    "auto_join6",
    "auto_join7",
    "auto_join8",
    "auto_join9"
```

We can remove all of them without affecting the test coverage.

### How was this patch tested?
N/A

Author: gatorsmile <gatorsmile@gmail.com>

Closes #14635 from gatorsmile/removeAuto.