!4592 【bugfix】master分支解决备机同时配置极致RTO和延迟回放时，Startup线程报错cannot wait on a latch owned by another process

Merge pull request !4592 from 周聪/bugfix_master_set_latch_error

src/include/access/xlog.h

@@ -555,6 +555,13 @@ typedef struct XLogCtlData {
      */
     Latch recoveryWakeupLatch;
 
+    /**
+     * used to wake up startup process in extroRtoMode and recovery_min_apply_delay > 0,
+     * to wake up startup process,  which is waiting in RecoveryApplyDelay(), to avoid 
+     * startup process contend for recoveryWakeupLatch with XLogPageRead process.
+     */
+    Latch recoveryWakeupDelayLatch;
+
     Latch dataRecoveryLatch;
 
     /*