PATCH [4.4]: update config.{guess,sub}

[Ben Elliston]

Hi Ralf

> Why are there changes from portable
>   grep ... >/dev/null
> to less portable but not any clearer
>   grep -q

I decided to use -q because I feel it is more compact and more readable.
grep -q is portable: it is defined in POSIX and it is supported by each
operating system that uses it in config.guess.  Systems for which future
patches may be supplied may not (just as they may not have grep!), but
that is up to the patch author to determine and find an alternative way.

> ?  That'll only help introduce other nonportable constructs in these
> scripts later.

I dispute that it is non-portable.

> How come dietlibc is not detected any more on Linux?

An oversight.  Thanks for catching this.

Ben