a tiny patch for IRA

[Vladimir Makarov]

I found that parent_max variable can be not used by code in macro 
SET_MINMAX_SET_BIT if release mode is used.  That results in generation 
of an unnecessary warning.

The following patch removes the warning and is committed as obvious.
2011-03-29  Vladimir Makarov <vmaka...@redhat.com>

        * ira-conflicts.c (build_object_conflicts): Add unused attribute
        to parent_max.

Index: ira-conflicts.c
===================================================================
--- ira-conflicts.c     (revision 171682)
+++ ira-conflicts.c     (working copy)
@@ -612,7 +612,7 @@ build_object_conflicts (ira_object_t obj)
   ira_allocno_t a = OBJECT_ALLOCNO (obj);
   IRA_INT_TYPE *object_conflicts;
   minmax_set_iterator asi;
-  int parent_min, parent_max;
+  int parent_min, parent_max ATTRIBUTE_UNUSED;
 
   object_conflicts = conflicts[OBJECT_CONFLICT_ID (obj)];
   px = 0;