issue#I5UDM6 LogAccessExclusiveLock() when primary

node acquire AccessExclusiveLock for systable

数据库中表（例如系统表pg_database在大量drop database情况下）因为vacuum时会触发
truncate操作，备机replay truncate操作的同时，有监控程序查询该表（
xlog_block_smgr_redo_truncate采用LockRelFileNode给该表的relfilenode加锁了，但
scan操作是通过LockRelationOid给relation的oid加锁，导致replay truncate和select操
作并行了），使被truncate操作invalid的buffer再次被加载到缓冲池中，在之后新的数据
插入到此原本应该已经invalid的数据页时产生错误。query在initscan时通过smgrnblocks
拿到nblocks，如果此时replay trucate log先做了InvalidateBuffer，再做
CacheInvalidateSmgr、smgr_truncate，会导致scan时再次讲invalid的buffer加载到
bufferpool中，产生错误。
回看pg代码，发现在lock relation时候，主机加AccessExclusiveLock时候会记录一条
XLOG_STANDBY_LOCK的日志，当备机回放到该日志时会加上AccessExclusiveLock。但是在
og中，因为原本分布式代码的残留，只在用户表时记了该日志，所以导致系统表会出现上
述问题。

src/gausskernel/storage/lmgr/lock.cpp

@@ -754,30 +754,8 @@ static LockAcquireResult LockAcquireExtendedXC(const LOCKTAG *locktag, LOCKMODE
      */
     if (lockmode >= AccessExclusiveLock && locktag->locktag_type == LOCKTAG_RELATION && !RecoveryInProgress() &&
         XLogStandbyInfoActive()) {
-        /*
-         * In a scenario like:
-         *
-         *	1, openGauss run vacuum full or autovacuum pg_class, insert AccessExclusiveLock xlog.
-         *	2, datanode crash, vacuum full abort.
-         *	3, datanode restart in pending mode, start recovery.
-         *	4, startup thread acquire pg_class's AccessExclusiveLock.
-         *	5, startup thread complete recovery and wait for notify.
-         *	6, cm agent connect datanode, need to init relcache file.
-         *	7, cm agent connect want to acquire pg_class's AccessShareLock,
-         *		but the AccessExclusiveLock lock is hold by startup thread.
-         *	8, dead lock, datanode hang.
-         *
-         *	Other system tables like pg_attribute/pg_type.. also have such problem.
-         *
-         *	To solve this problem, we don't insert AccessExclusiveLock xlog for system tables.
-         *	This change may cause exception when primary run vacuum full system table while
-         *	standby access the system table at the same time.
-         *
-         */
-        if (locktag->locktag_field2 > FirstNormalObjectId) {
-            LogAccessExclusiveLockPrepare();
-            log_lock = true;
-        }
+        LogAccessExclusiveLockPrepare();
+        log_lock = true;
     }
 
     /*