Building PVS on ARM-based Macs

[Kai Engelhardt]

It would be great if others could test out my build instructions so we catch problems before this can – maybe – make it into the official distribution.

tl;dr use the most recent master (commit 2df1760); apply a trivial patch for few C files in src/bdd

I'm almost certain that my instructions are incomplete because I build on a system with a few other things already installed. Please test and report back!