cc/gcc: frontends are responsible for selecting the list of languages

Do for the final step the same as for the core step: compute the list
of selected langauages from the frontend, not in the backend.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

#!/bin/sh

set -e

printf "Running autoconf...\n"

autoconf -Wall --force

printf "Done. You may now run:\n    ./configure\n"