Run conform/ tests using newly built libc

[Florian Weimer]

* Joseph Myers:

> diff --git a/Makeconfig b/Makeconfig
> index 68663d984e..2fa0884b4e 100644
> --- a/Makeconfig
> +++ b/Makeconfig

The Makeconfig changes look okay to me.  The effect of the -o option is
not affected by the other command line arguments, so moving it around
within the command line should not make a difference.

Thanks,
Florian