This prevents failures like "libgcc_s.so.1 must be installed for
pthread_cancel to work" that occur because Glibc assumes libgcc_s.so.1
to be in Glibc's libdir.
This solution is pretty hacky, because the libgcc_s.so.1 from
bootstrap-tools might be too old. So if we update GCC, programs might
end up using an outdated libgcc_s.so.1. Ideally, we would build
libgcc_s.so.1 *before* Glibc, which might not be impossible...
Fixes#3548.
to be in the buildInputs). While at it, update to
version 4.2. "attr" is no longer needed as a dependency.
svn path=/nixpkgs/branches/stdenv-updates/; revision=31744
