MDEV-26784 [Warning] InnoDB: Difficult to find free blocks in the buffer pool

Problem:
=======
  InnoDB ran out of memory during recovery and it fails to
flush the dirty LRU blocks. The reason is that buffer pool
can ran out before the LRU list length reaches
BUF_LRU_OLD_MIN_LEN(256) threshold.

Fix:
====
During recovery, InnoDB should write out and evict all
dirty blocks.

mysql-test/suite/innodb/r/recovery_memory.result

+CREATE TABLE t1(c TEXT, KEY(c(3072)))ENGINE=InnoDB;
+CREATE PROCEDURE dorepeat()
+LOOP
+INSERT INTO t1 VALUES ('abc');
+UPDATE t1 SET c='cba';
+END LOOP
+|
+connect con1,localhost,root,,,;
+CALL dorepeat();
+connection default;
+# restart: --innodb_buffer_pool_size=5242880
+DROP TABLE t1;

mysql-test/suite/innodb/t/recovery_memory.opt

+--innodb_buffer_pool_size=1073741824

mysql-test/suite/innodb/t/recovery_memory.test

+--source include/have_innodb.inc
+--source include/big_test.inc
+CREATE TABLE t1(c TEXT, KEY(c(3072)))ENGINE=InnoDB;
+DELIMITER |;
+
+CREATE PROCEDURE dorepeat()
+  LOOP
+   INSERT INTO t1 VALUES ('abc');
+   UPDATE t1 SET c='cba';
+  END LOOP
+|
+
+DELIMITER ;|
+connect(con1,localhost,root,,,);
+send CALL dorepeat();
+connection default;
+sleep 10;
+let $shutdown_timeout=0;
+let $restart_parameters=--innodb_buffer_pool_size=5242880;
+--source include/restart_mysqld.inc
+DROP TABLE t1;

storage/innobase/buf/buf0flu.cc

@@ -1288,9 +1288,11 @@ static void buf_flush_LRU_list_batch(ulint max, flush_counters_t *n)
   static_assert(FIL_NULL > SRV_SPACE_ID_UPPER_BOUND, "consistency");
 
   for (buf_page_t *bpage= UT_LIST_GET_LAST(buf_pool.LRU);
-       bpage && n->flushed + n->evicted < max &&
-       UT_LIST_GET_LEN(buf_pool.LRU) > BUF_LRU_MIN_LEN &&
-       UT_LIST_GET_LEN(buf_pool.free) < free_limit; ++scanned)
+       bpage &&
+       ((UT_LIST_GET_LEN(buf_pool.LRU) > BUF_LRU_MIN_LEN &&
+         UT_LIST_GET_LEN(buf_pool.free) < free_limit &&
+         n->flushed + n->evicted < max) ||
+        recv_recovery_is_on()); ++scanned)
   {
     buf_page_t *prev= UT_LIST_GET_PREV(LRU, bpage);
     const lsn_t oldest_modification= bpage->oldest_modification();