MDEV-37777 upgrade from MySQL 5.7 regression, mysql.servers invalid structure

Revert the fix for MDEV-35622 (957ec8b).

mysql.servers structure differs in different versions
of MariaDB and MySQL, cannot use Table_check_intact to validate it.

Author: vuvova

mysql-test/main/grant_repair.result

@@ -88,15 +88,6 @@ create role r1;
 drop role r1;
 rename table mysql.roles_mapping_bak to mysql.roles_mapping;
 #
-# MDEV-35622 SEGV, ASAN use-after-poison when reading system table with less than expected number of columns
-#
-call mtr.add_suppression("mysql.servers");
-alter table mysql.servers drop column owner;
-insert into mysql.servers values(0,0,0,0,0,0,0,0);
-flush privileges;
-ERROR HY000: Cannot load from mysql.servers. The table is probably corrupted
-alter table mysql.servers add column Owner varchar(512) not null default '';
-#
 # MDEV-28482 SIGSEGV in get_access_value_from_val_int
 #
 create temporary table t1 select * from mysql.tables_priv;

mysql-test/main/grant_repair.test

@@ -104,16 +104,6 @@ create role r1;
 drop role r1;
 rename table mysql.roles_mapping_bak to mysql.roles_mapping;
 
---echo #
---echo # MDEV-35622 SEGV, ASAN use-after-poison when reading system table with less than expected number of columns
---echo #
-call mtr.add_suppression("mysql.servers");
-alter table mysql.servers drop column owner;
-insert into mysql.servers values(0,0,0,0,0,0,0,0);
---error ER_CANNOT_LOAD_FROM_TABLE_V2
-flush privileges;
-alter table mysql.servers add column Owner varchar(512) not null default '';
-
 --echo #
 --echo # MDEV-28482 SIGSEGV in get_access_value_from_val_int
 --echo #

sql/sql_servers.cc

@@ -56,61 +56,6 @@ static MEM_ROOT mem;
 static mysql_rwlock_t THR_LOCK_servers;
 static LEX_CSTRING MYSQL_SERVERS_NAME= {STRING_WITH_LEN("servers") };
 
-static const TABLE_FIELD_TYPE servers_table_fields[] =
-{
-  {
-    { STRING_WITH_LEN("Server_name") },
-    { STRING_WITH_LEN("char(") },
-    { STRING_WITH_LEN("utf8mb") }
-  },
-  {
-    { STRING_WITH_LEN("Host") },
-    { STRING_WITH_LEN("varchar(") },
-    { STRING_WITH_LEN("utf8mb") }
-  },
-  {
-    { STRING_WITH_LEN("Db") },
-    { STRING_WITH_LEN("char(") },
-    { STRING_WITH_LEN("utf8mb") }
-  },
-  {
-    { STRING_WITH_LEN("Username") },
-    { STRING_WITH_LEN("char(") },
-    { STRING_WITH_LEN("utf8mb") }
-  },
-  {
-    { STRING_WITH_LEN("Password") },
-    { STRING_WITH_LEN("char(") },
-    { STRING_WITH_LEN("utf8mb") }
-  },
-  {
-    { STRING_WITH_LEN("Port") },
-    { STRING_WITH_LEN("int(") },
-    {NULL, 0}
-  },
-  {
-    { STRING_WITH_LEN("Socket") },
-    { STRING_WITH_LEN("char(") },
-    { STRING_WITH_LEN("utf8mb") }
-  },
-  {
-    { STRING_WITH_LEN("Wrapper") },
-    { STRING_WITH_LEN("char(") },
-    { STRING_WITH_LEN("utf8mb") }
-  },
-  {
-    { STRING_WITH_LEN("Owner") },
-    { STRING_WITH_LEN("varchar(") },
-    { STRING_WITH_LEN("utf8mb") }
-  }
-};
-static const TABLE_FIELD_DEF servers_table_def=
-{
-  array_elements(servers_table_fields), servers_table_fields, 0, NULL
-};
-
-static Table_check_intact_log_error table_intact;
-
 static bool get_server_from_table_to_cache(TABLE *table);
 
 /* insert functions */
@@ -408,13 +353,6 @@ bool servers_reload(THD *thd)
     goto end;
   }
 
-  if (table_intact.check(tables.table, &servers_table_def))
-  {
-    my_error(ER_CANNOT_LOAD_FROM_TABLE_V2, MYF(0),
-             tables.db.str, tables.table_name.str);
-    goto end;
-  }
-
   if ((return_val= servers_load(thd, &tables)))
   {					// Error. Revert to old list
     /* blast, for now, we have no servers, discuss later way to preserve */