re PR c++/12909 (ambiguity in mangling vector types)

	PR c++/12909
	* mangle.c (write_type): Give -Wabi warning for old vector mangling.

From-SVN: r157052

gcc/cp/ChangeLog

 2010-02-24  Jason Merrill  <jason@redhat.com>
 
+	PR c++/12909
+	* mangle.c (write_type): Give -Wabi warning for old vector mangling.
+
 	* class.c (layout_class_type): Don't give -Wabi warning for a bug
 	in a previous ABI version.
 

gcc/cp/mangle.c

@@ -1904,7 +1904,10 @@ write_type (tree type)
 		  write_char ('_');
 		}
 	      else
-		write_string ("U8__vector");
+		{
+		  G.need_abi_warning = 1;
+		  write_string ("U8__vector");
+		}
 	      write_type (TREE_TYPE (type));
 	      break;