sql_sizing

Hi All, 
I've got an issue that I've been trying to track down some results to.
I've noticed that on a recent PostgreSQL server that I've been working
on has a few relations that do not exist:

select relname, relnamespace, reltype from pg_class where relname ~*
'sql_';        relname         | relnamespace | reltype 
-------------------------+--------------+---------sql_features            |        16977 |
17071sql_implementation_info|        16977 |   17076sql_languages           |        16977 |   17081sql_packages
   |        16977 |   17086sql_sizing              |        16977 |   17091sql_sizing_profiles     |        16977 |
17096
(6 rows)
These tables are in the pg_class table, but no where on any PostgreSQL
server that I've been able to look at have these tables been created.
I've been working with 7.4.1 and 7.4.2 versions, and have even initdb'd
a couple of databases only to find that they are not getting created
even though they are being listed in the pg_class table. 
I've been working with a series of scripts that floats over the
pg_class table to find a listing of all tables that exist. That was when
I noticed that these ones did not.
Has anyone else run into this problem?, is it safe to remove these
tables from the pg_class table or is it safe to create the tables
themselves?

-- 
Chris Bowlby <chris@pgsql.com>
PostgreSQL Inc.