[SPARK-11633][SQL] LogicalRDD throws TreeNode Exception : Failed to Copy Node

When handling self joins, the implementation did not consider the case insensitivity of HiveContext. It could cause an exception as shown in the JIRA:
```
TreeNodeException: Failed to copy node.
```

The fix is low risk. It avoids unnecessary attribute replacement. It should not affect the existing behavior of self joins. Also added the test case to cover this case.

Author: gatorsmile <gatorsmile@gmail.com>

Closes #9762 from gatorsmile/joinMakeCopy.