* distro/packages/base.scm (%static-inputs): Add an `awk' -> `gawk', and
`sh' -> `bash' symlinks. Add `fgrep' and `egrep'.
(%bootstrap-coreutils&co): Use new tarball that contains that
symlink.
* distro/packages/bootstrap/x86_64-linux/bash,
distro/packages/bootstrap/x86_64-linux/mkdir,
distro/packages/bootstrap/x86_64-linux/tar,
distro/packages/bootstrap/x86_64-linux/xz: Use binaries from that
tarball (the previous binaries hadn't gone through
`remove-store-references', which is fixed now.)