Make the system-attributes loop in AddNewAttributeTuples depend on

lengthof(SysAtt) not FirstLowInvalidHeapAttributeNumber, for consistency with
the other uses of the SysAtt array, and to make it clearer that it doesn't
walk off the end of that array.

src/backend/catalog/heap.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/catalog/heap.c,v 1.340 2008/09/30 10:52:12 heikki Exp $
+ *	  $PostgreSQL: pgsql/src/backend/catalog/heap.c,v 1.341 2008/10/14 23:27:40 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -551,7 +551,7 @@ AddNewAttributeTuples(Oid new_rel_oid,
 	if (relkind != RELKIND_VIEW && relkind != RELKIND_COMPOSITE_TYPE)
 	{
 		dpp = SysAtt;
-		for (i = 0; i < -1 - FirstLowInvalidHeapAttributeNumber; i++)
+		for (i = 0; i < (int) lengthof(SysAtt); i++, dpp++)
 		{
 			if (tupdesc->tdhasoid ||
 				(*dpp)->attnum != ObjectIdAttributeNumber)
@@ -587,7 +587,6 @@ AddNewAttributeTuples(Oid new_rel_oid,
 
 				heap_freetuple(tup);
 			}
-			dpp++;
 		}
 	}