The commit xlog record carries the information for objects which serves us for
crash-recovery till post-commit persistent object work is done, hence cannot
allow checkpoint in between. So, use inCommit flag to achieve the same. This
makes it consistent with FinishPreparedTransaction() as well.

Without the fix leaves out dangling persistent table entries and files on-disk
for following sequence:

- start transaction to drop a table
- `RecordTransactionCommit()`
- Checkpoint before `AtEOXact_smgr()`
- Crash/Recover