[PATCH] Fix AIX build break.

[Tom Tromey]

>>>>> "Ciaran" == Ciaran Woodward <ciaranwoodward@xmos.com> writes:

Ciaran> I think it is because va_list on that platform has some attributes.

Ugh.

Ciaran>  scoped_restore_warning_hook::scoped_restore_warning_hook
Ciaran>       (warning_hook_handler new_handler)
Ciaran> -       : m_save (make_scoped_restore (&warning_hook, new_handler))
Ciaran> +       : m_save (make_scoped_restore (reinterpret_cast<void(**)()>(&warning_hook),
Ciaran> +                                      reinterpret_cast<void(*)()>(new_handler)))

What if we remove the scoped_restore use and just do the save/restore
manually here instead?

Tom