Fix completely-bogus volatility markings on pg_trgm functions.

contrib/pg_trgm/pg_trgm.sql.in

-/* $PostgreSQL: pgsql/contrib/pg_trgm/pg_trgm.sql.in,v 1.6 2007/11/13 04:24:28 momjian Exp $ */
+/* $PostgreSQL: pgsql/contrib/pg_trgm/pg_trgm.sql.in,v 1.7 2007/12/09 02:22:46 tgl Exp $ */
 
 -- Adjust this setting to control where the objects get created.
 SET search_path = public;
@@ -6,12 +6,12 @@ SET search_path = public;
 CREATE OR REPLACE FUNCTION set_limit(float4)
 RETURNS float4
 AS 'MODULE_PATHNAME'
-LANGUAGE C STRICT IMMUTABLE;
+LANGUAGE C STRICT VOLATILE;
 
 CREATE OR REPLACE FUNCTION show_limit()
 RETURNS float4
 AS 'MODULE_PATHNAME'
-LANGUAGE C STRICT IMMUTABLE;
+LANGUAGE C STRICT STABLE;
 
 CREATE OR REPLACE FUNCTION show_trgm(text)
 RETURNS _text
@@ -26,7 +26,7 @@ LANGUAGE C STRICT IMMUTABLE;
 CREATE OR REPLACE FUNCTION similarity_op(text,text)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C STRICT IMMUTABLE;
+LANGUAGE C STRICT STABLE;
 
 CREATE OPERATOR % (
         LEFTARG = text,