Document va_copy in preference to __va_copy

[Roland McGrath]

>  @comment stdarg.h
> +@comment ISO
> +@deftypefn {Macro} void va_copy (va_list @var{dest}, va_list @var{src})
>  @comment GNU
> -@deftypefn {Macro} void __va_copy (va_list @var{dest}, va_list @var{src})

Need to remove the @comment GNU since @comment ISO replaces it.
Otherwise this looks fine.


Thanks,
Roland