At least for the TriCore target no easily available c compiler exists.
Thus we need to rely on "as" and "ld". This allows us to run them
through the docker image. We don't test the generation capabilities of
docker images as they are assumed to work.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
[AJB: fix quoting, only handle docker & clear, test -n, tweak commit msg]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20210512102051.12134-12-alex.bennee@linaro.org>