[SPARK-3705][SQL]add case for VoidObjectInspector to cover NullType

[scwf]

add case for VoidObjectInspector in inspectorToDataType

[AmplabJenkins]

Can one of the admins verify this patch?

[marmbrus]

ok to test

[SparkQA]

QA tests have started for PR 2552 at commit 453d892.

• This patch merges cleanly.

[SparkQA]

Tests timed out after a configured wait of 120m.

[AmplabJenkins]

Test FAILed.
Refer to this link for build results (access rights to CI server needed):
https://amplab.cs.berkeley.edu/jenkins//job/SparkPullRequestBuilder/20922/

[scwf]

@marmbrus , it seems all PR of SQL tests timed out

[scwf]

I tested for the time out issue, #1689 lead to this issue, but have not found the root cause

[scwf]

@marmbrus, test this and #2551, they failed due to time out, thanks

[scwf]

@pwendell, can you help to test this and #2551, i did not have the access for jenkins test

[marmbrus]

Sorry, I've been really busy and haven't had time to review PRs. Starting tests now. Pending those this LGTM.

[SparkQA]

QA tests have started for PR 2552 at commit 453d892.

• This patch merges cleanly.

[SparkQA]

QA tests have finished for PR 2552 at commit 453d892.

• This patch passes unit tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class PStatsParam(AccumulatorParam):

[marmbrus]

Thanks! Merged to master.