If during releaseMemory we fail to write to disk, then the output of the future getMore operations can be unpredictable. To be safer, we should destroy the cursor.

Currently expected errors could be:
1. CursorInUse - cursor is already pinned by getMore, we could not corrupted it.
2. Interrupted - operation was interrupted by a user and we only check for interruptions in fixed places.
3. NoDiskUseAllowed - release memory was not allowed to write anything to disk, so it couldn't mess with the cursor
4. OutOfDiskSpace - This might happen at any moment during spilling (SERVER-104360) leaving the cursor in a corrupted state