[Nix-dev] gcc-wrapper depends on coreutils

[Lluís Batlle]

Hello,

I've seen some of the gcc-wrapper scripts depend on coreutils' cat
(see add-flags.sh and gcc-wrapper.sh)
I would like that 'cat' is used from a proper coreutils path, with its
derivation stated, and I tried to do that in stdenv-updates so it does
not end forgotten.
We can revert the patch if you think the coreutils should not be
stated as a dependency, but I would like to know some arguments about
it. stdenv experts, please review the patch.

I noticed the lack of 'cat' when I was using ikiwiki, which uses gcc
to compile programs, but it did not have coreutils in its path.

Thank you in advance,
Lluís.