Backport of subquery optimizations to 5.3.

There are still test failures because of:
- Wrong query results in outer join + semi join
- EXPLAIN output differences

sql/sql_update.cc

@@ -1797,7 +1797,9 @@ bool multi_update::send_data(List<Item> &not_used_values)
       {
         if (error &&
             create_internal_tmp_table_from_heap(thd, tmp_table,
-                                    tmp_table_param + offset, error, 1))
+                                         tmp_table_param[offset].start_recinfo,
+                                         &tmp_table_param[offset].recinfo,
+                                         error, 1))
         {
           do_update= 0;
           DBUG_RETURN(1);			// Not a table_is_full error