Mark to_char(timestamp without timezone) as stable, not immutable, since its

result now depends on the lc_messages setting, as noted by Bruce.
Also, mark to_number() and the numeric-type variants of to_char() as stable,
because their results depend on lc_numeric; this is a longstanding oversight.
Also, mark to_date() and to_char(interval) as stable; although these appear
not to depend on any GUC variables as of CVS HEAD, that seems a property
unlikely to survive future improvements.  It seems best to mark all the
formatting functions stable and be done with it.
catversion not bumped, because this does not seem critical enough to force
a post-RC1 initdb, and anyway we cannot do so in the back branches.

src/include/catalog/pg_proc.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.428 2006/11/24 21:18:42 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.429 2006/11/28 19:18:44 tgl Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -2614,23 +2614,23 @@ DESCR("(internal)");
 /* formatting */
 DATA(insert OID = 1770 ( to_char			PGNSP PGUID 12 f f t f s 2	25 "1184 25" _null_ _null_ _null_  timestamptz_to_char - _null_ ));
 DESCR("format timestamp with time zone to text");
-DATA(insert OID = 1772 ( to_char			PGNSP PGUID 12 f f t f i 2	25 "1700 25" _null_ _null_ _null_  numeric_to_char - _null_ ));
+DATA(insert OID = 1772 ( to_char			PGNSP PGUID 12 f f t f s 2	25 "1700 25" _null_ _null_ _null_  numeric_to_char - _null_ ));
 DESCR("format numeric to text");
-DATA(insert OID = 1773 ( to_char			PGNSP PGUID 12 f f t f i 2	25 "23 25" _null_ _null_ _null_ int4_to_char - _null_ ));
+DATA(insert OID = 1773 ( to_char			PGNSP PGUID 12 f f t f s 2	25 "23 25" _null_ _null_ _null_ int4_to_char - _null_ ));
 DESCR("format int4 to text");
-DATA(insert OID = 1774 ( to_char			PGNSP PGUID 12 f f t f i 2	25 "20 25" _null_ _null_ _null_ int8_to_char - _null_ ));
+DATA(insert OID = 1774 ( to_char			PGNSP PGUID 12 f f t f s 2	25 "20 25" _null_ _null_ _null_ int8_to_char - _null_ ));
 DESCR("format int8 to text");
-DATA(insert OID = 1775 ( to_char			PGNSP PGUID 12 f f t f i 2	25 "700 25" _null_ _null_ _null_	float4_to_char - _null_ ));
+DATA(insert OID = 1775 ( to_char			PGNSP PGUID 12 f f t f s 2	25 "700 25" _null_ _null_ _null_	float4_to_char - _null_ ));
 DESCR("format float4 to text");
-DATA(insert OID = 1776 ( to_char			PGNSP PGUID 12 f f t f i 2	25 "701 25" _null_ _null_ _null_	float8_to_char - _null_ ));
+DATA(insert OID = 1776 ( to_char			PGNSP PGUID 12 f f t f s 2	25 "701 25" _null_ _null_ _null_	float8_to_char - _null_ ));
 DESCR("format float8 to text");
-DATA(insert OID = 1777 ( to_number			PGNSP PGUID 12 f f t f i 2	1700 "25 25" _null_ _null_ _null_  numeric_to_number - _null_ ));
+DATA(insert OID = 1777 ( to_number			PGNSP PGUID 12 f f t f s 2	1700 "25 25" _null_ _null_ _null_  numeric_to_number - _null_ ));
 DESCR("convert text to numeric");
 DATA(insert OID = 1778 ( to_timestamp		PGNSP PGUID 12 f f t f s 2	1184 "25 25" _null_ _null_ _null_  to_timestamp - _null_ ));
 DESCR("convert text to timestamp with time zone");
-DATA(insert OID = 1780 ( to_date			PGNSP PGUID 12 f f t f i 2	1082 "25 25" _null_ _null_ _null_  to_date - _null_ ));
+DATA(insert OID = 1780 ( to_date			PGNSP PGUID 12 f f t f s 2	1082 "25 25" _null_ _null_ _null_  to_date - _null_ ));
 DESCR("convert text to date");
-DATA(insert OID = 1768 ( to_char			PGNSP PGUID 12 f f t f i 2	25 "1186 25" _null_ _null_ _null_  interval_to_char - _null_ ));
+DATA(insert OID = 1768 ( to_char			PGNSP PGUID 12 f f t f s 2	25 "1186 25" _null_ _null_ _null_  interval_to_char - _null_ ));
 DESCR("format interval to text");
 
 DATA(insert OID =  1282 ( quote_ident	   PGNSP PGUID 12 f f t f i 1 25 "25" _null_ _null_ _null_ quote_ident - _null_ ));
@@ -3035,7 +3035,7 @@ DATA(insert OID = 2047 (  timetz			PGNSP PGUID 12 f f t f s 1 1266 "1083" _null_
 DESCR("convert time to timetz");
 DATA(insert OID = 2048 (  isfinite			PGNSP PGUID 12 f f t f i 1	 16 "1114" _null_ _null_ _null_ timestamp_finite - _null_ ));
 DESCR("finite timestamp?");
-DATA(insert OID = 2049 ( to_char			PGNSP PGUID 12 f f t f i 2	25 "1114 25" _null_ _null_ _null_  timestamp_to_char - _null_ ));
+DATA(insert OID = 2049 ( to_char			PGNSP PGUID 12 f f t f s 2	25 "1114 25" _null_ _null_ _null_  timestamp_to_char - _null_ ));
 DESCR("format timestamp to text");
 DATA(insert OID = 2052 (  timestamp_eq		PGNSP PGUID 12 f f t f i 2 16 "1114 1114" _null_ _null_ _null_	timestamp_eq - _null_ ));
 DESCR("equal");