[lto] Use nth_parm_type in merge_types.

[Kazu Hirata]

Hi,

Tested on x86_64-pc-linux-gnu.  Committed to the LTO branch as
obvious.

Kazu Hirata

2006-07-03  Kazu Hirata  <kazu@codesourcery.com>

	* typeck.c (merge_types): Use nth_parm_type.

Index: cp/typeck.c
===================================================================
--- cp/typeck.c	(revision 115069)
+++ cp/typeck.c	(working copy)
@@ -684,7 +684,7 @@ merge_types (tree t1, tree t2)
       {
 	/* Get this value the long way, since TYPE_METHOD_BASETYPE
 	   is just the main variant of this.  */
-	tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
+	tree basetype = TREE_TYPE (nth_parm_type (TYPE_ARG_TYPES (t2), 0));
 	tree raises = TYPE_RAISES_EXCEPTIONS (t1);
 	tree t3;