Re: [PATCH] ci: make MAKEFLAGS available inside the Docker container in the Linux32 job

> Once upon a time we ran 'make --jobs=2 ...' to build Git, its
> documentation, or to apply Coccinelle semantic patches.  Then commit
> eaa62291ff (ci: inherit --jobs via MAKEFLAGS in run-build-and-tests,
> 2019-01-27) came along, and started using the MAKEFLAGS environment
> variable to centralize setting the number of parallel jobs in
> 'ci/libs.sh'.  Alas, it forgot to update 'ci/run-linux32-docker.sh' to
> make MAKEFLAGS available inside the Docker container running the 32
> bit Linux job, and, consequently, since then that job builds Git
> sequentially, and it ignores any Makefile knobs that we might set in
> MAKEFLAGS (though we don't set any for the 32 bit Linux job at the
> moment).
>
> So update the 'docker run' invocation in 'ci/run-linux32-docker.sh' to
> make MAKEFLAGS available inside the Docker container as well.  Set
> CC=gcc for the 32 bit Linux job, because that's the compiler installed
> in the 32 bit Linux Docker image that we use (Travis CI nowadays sets
> CC=clang by default, but clang is not installed in this image).
>
> Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
> ---
>
> The 'dd/musl-libc-travis-ci' topic needs some more updates, and those
> will depend on this fix.