MDEV-24622: Replication does not support bulk insert into empty table

Remove work-around that disables bulk insert optimization in replication

The root cause of the original problem is now fixed (MDEV-33475). Though the
bulk insert optimization will still be disabled in replication, as it is
only enabled in special circumstances meant for loading a mysqldump.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

sql/sql_class.cc

@@ -5317,14 +5317,6 @@ extern "C" enum enum_server_command thd_current_command(MYSQL_THD thd)
   return thd->get_command();
 }
 
-#ifdef HAVE_REPLICATION /* Working around MDEV-24622 */
-/** @return whether the current thread is for applying binlog in a replica */
-extern "C" int thd_is_slave(const MYSQL_THD thd)
-{
-  return thd && thd->slave_thread;
-}
-#endif /* HAVE_REPLICATION */
-
 /* Returns high resolution timestamp for the start
   of the current query. */
 extern "C" unsigned long long thd_start_utime(const MYSQL_THD thd)

storage/innobase/row/row0ins.cc

@@ -2565,12 +2565,6 @@ row_ins_index_entry_big_rec(
 	return(error);
 }
 
-#ifdef HAVE_REPLICATION /* Working around MDEV-24622 */
-extern "C" int thd_is_slave(const MYSQL_THD thd);
-#else
-# define thd_is_slave(thd) 0
-#endif
-
 #if defined __aarch64__&&defined __GNUC__&&__GNUC__==4&&!defined __clang__
 /* Avoid GCC 4.8.5 internal compiler error due to srw_mutex::wr_unlock().
 We would only need this for row_ins_clust_index_entry_low(),
@@ -2722,8 +2716,7 @@ row_ins_clust_index_entry_low(
 	    && !index->table->skip_alter_undo
 	    && !index->table->n_rec_locks
 	    && !index->table->is_active_ddl()
-	    && !index->table->versioned()
-	    && !thd_is_slave(trx->mysql_thd) /* FIXME: MDEV-24622 */) {
+	    && !index->table->versioned()) {
 		DEBUG_SYNC_C("empty_root_page_insert");
 
 		if (!index->table->is_temporary()) {