+extern bool hook_bool_rtx_commutative_p (rtx, int);
+extern rtx default_function_value (tree, tree, bool);
+extern rtx default_internal_arg_pointer (void);
+extern enum reg_class default_secondary_reload (bool, rtx, enum reg_class,
+ enum machine_mode,
+ secondary_reload_info *);
+extern void hook_void_bitmap (bitmap);