Fixed bugs found by mysql-test-run:

- privilege_table_io.test didn't properly reset roles_mapping
- Fixed memory allocation problem with CHECK CONSTRAINT, found when
  running --valgrind main.check_constraint

mysql-test/suite/perfschema/r/privilege_table_io.result

@@ -15,6 +15,7 @@ optimize table mysql.proxies_priv;
 optimize table mysql.tables_priv;
 optimize table mysql.procs_priv;
 optimize table mysql.servers;
+optimize table mysql.roles_mapping;
 update performance_schema.setup_consumers set enabled='YES';
 update performance_schema.setup_objects set enabled='YES'
   where object_type='TABLE' and object_schema= 'mysql';

mysql-test/suite/perfschema/t/privilege_table_io.test

@@ -24,6 +24,7 @@ optimize table mysql.proxies_priv;
 optimize table mysql.tables_priv;
 optimize table mysql.procs_priv;
 optimize table mysql.servers;
+optimize table mysql.roles_mapping;
 --enable_result_log
 
 # Start recording events

sql/table.cc

@@ -3110,7 +3110,8 @@ enum open_frm_error open_table_from_share(THD *thd, TABLE_SHARE *share,
                                                 share->default_expressions +1)*
                                                sizeof(Field*)),
                           &check_constraint_ptr,
-                          (uint) ((share->table_check_constraints + 1)*
+                          (uint) ((share->table_check_constraints +
+                                   share->field_check_constraints + 1)*
                                   sizeof(Virtual_column_info*)),
                           NullS))
       goto err;