[sqlsmith] ERROR: failed to build any %d-way joins

Hi,

there's a 1/1e6 chance that a sqlsmith query on the regression db of
master (c124cef) fails with
   ERROR:  failed to build any {4..8}-way joins

They all appear to work fine on REL9_5_STABLE.

sample query:

select 1 from information_schema.collations as rel_60113935  inner join information_schema.sql_sizing_profiles as
rel_60113936 on (rel_60113935.pad_attribute = rel_60113936.sizing_name )inner join information_schema.foreign_tables as
rel_60113937on(rel_60113936.profile_id = rel_60113937.foreign_table_catalog )     right join
information_schema.constraint_table_usageas rel_60113938     on (rel_60113935.collation_schema =
rel_60113938.table_catalog)   left join public.btree_tall_tbl as rel_60113939   on (rel_60113936.required_value =
rel_60113939.id)
 
where rel_60113938.table_name is not NULL;

regards,
Andreas