Gitlab also provides runners with Windows, we can use them to
test compilation with MSYS2, in both, 64-bit and 32-bit.

However, it takes quite a long time to set up the VM, so to stay
in a reasonable time frame, we can only compile and check one
target here.

Message-Id: <20211115140623.104116-1-thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>