RE: Parallel INSERT SELECT take 2

From: houzj.fnst@fujitsu.com 
> Hi,
> 
> When testing the patch, I found some issues in the 0003,0004 patch.
> Attaching new version patchset which fix these issues.
> 
> 0003
> * don't check parallel safety of partition's default column expression.
> * rename some function/variable names to be consistent with existing code.
> * remove some unused function parameters.
> * fix a max_hazard overwrite issue.
> * add some code comments and adjust some code forms.
> 
> 0004
> * Remove some unrelated comments in the regression test.
> * add the 'begin;', 'rollback;' in insert_parallel.sql.

Through further review and thanks for greg-san's suggestions,
I attached a new version patchset with some minor change in 0001,0003 and 0004.

0001.
* fix a typo in variable name.
* add a TODO in patch comment about updating the version number when branch PG15.

0003
* fix a 'git apply white space' warning.
* Remove some unnecessary if condition.
* add some code comments above the safety check function.
* Fix some typo.

0004
* add a testcase to test ALTER PARALLEL DML UNSAFE/RESTRICTED.

Best regards,
houzj