Compiling an empty program leads to a core dump in 12:wlur

In the most recent commit on the develop branch (c21cf938), SaC dumps the core when trying to compile an empty program in the with-loop unrolling step.
This bug is not yet present in the 1.3.3-MijasCosta-705-g41ed2 release.

I'd attach a minimum working example but if you're in the build folder it's literally just touch test-empty.sac && ./sac2c_d test-empty.sac