Properly mark pg_freespace() function as strict. Also update

uninstall script to match reality.

contrib/pg_freespacemap/pg_freespacemap.sql.in

-/* $PostgreSQL: pgsql/contrib/pg_freespacemap/pg_freespacemap.sql.in,v 1.11 2008/10/02 12:20:50 heikki Exp $ */
+/* $PostgreSQL: pgsql/contrib/pg_freespacemap/pg_freespacemap.sql.in,v 1.12 2009/06/10 22:12:28 tgl Exp $ */
 
 -- Adjust this setting to control where the objects get created.
 SET search_path = public;
@@ -8,7 +8,7 @@ SET search_path = public;
 CREATE OR REPLACE FUNCTION pg_freespace(regclass, bigint)
 RETURNS int2
 AS 'MODULE_PATHNAME', 'pg_freespace'
-LANGUAGE C;
+LANGUAGE C STRICT;
 
 -- pg_freespace shows the recorded space avail at each block in a relation
 CREATE OR REPLACE FUNCTION

contrib/pg_freespacemap/uninstall_pg_freespacemap.sql

-/* $PostgreSQL: pgsql/contrib/pg_freespacemap/uninstall_pg_freespacemap.sql,v 1.4 2008/09/30 11:17:07 heikki Exp $ */
+/* $PostgreSQL: pgsql/contrib/pg_freespacemap/uninstall_pg_freespacemap.sql,v 1.5 2009/06/10 22:12:28 tgl Exp $ */
 
 -- Adjust this setting to control where the objects get dropped.
 SET search_path = public;
 
-DROP VIEW pg_freespacemap_pages;
-DROP VIEW pg_freespacemap_relations;
-
-DROP FUNCTION pg_freespacemap_pages();
-DROP FUNCTION pg_freespacemap_relations();
+DROP FUNCTION pg_freespace(regclass, bigint);
+DROP FUNCTION pg_freespace(regclass);