* diagnostic.c (init_output_buffer): Don't initialize format_args.
        (output_clear): Likewise.
        (output_printf): Use va_copy.
        (vline_wrapper_message_with_location): Likewise.
        (v_message_with_decl): Likewise.
        (line_wrapper_printf): VA_START infor buffer.format_args directly.
        * system.h (va_copy): Provide default implementation.

From-SVN: r33341