dwarf2out.c (add_abstract_origin_attribute): Don't abort when the original die cannot be found.

	* dwarf2out.c (add_abstract_origin_attribute): Don't abort when
	the original die cannot be found.

From-SVN: r30787

gcc/dwarf2out.c

@@ -7503,7 +7503,7 @@ add_abstract_origin_attribute (die, origin)
     origin_die = lookup_type_die (origin);
 
   if (origin_die == NULL)
-    abort ();
+    return;
   
   add_AT_die_ref (die, DW_AT_abstract_origin, origin_die);
 }