Include last block in FSM vacuum of bulk extended relation

Include last block in FSM vacuum of bulk extended relation

When bulk-extending a relation, we add the newly-added blocks that we
won't immediately use to the free space map and then call
FreeSpaceMapVacuumRange() to propagate that free space up the FSM tree,
so other backends can find and reuse it.

However, the end block argument to FreeSpaceMapVacuumRange() is
exclusive, and we passed the number of the last added block (since
00d1e02be24). If that block was the first one covered by a new FSM page,
its free space wasn't propagated up the tree and was therefore invisible
to FSM searches until the next FSM vacuum.

Fix by passing the block number one past the last added block, so the
full range is vacuumed.

Author: Jingtang Zhang <mrdrivingduck@gmail.com>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/flat/CAPsk3_Bx_vdybN%3D-DZu8HLStf%2BXnuFUBkLwxouONSMkWuO9oug%40mail.gmail.com
Backpatch-through: 16