Pushed now. If anything breaks please let me know.
This cleanup was kickstarted when I tried to compile 7.9 with Clang. I still see wrong execution in e.g. integer/bignum handling so I hope to have more patches in the coming days. One of my other findings was the commit aabfb4f04c5 (precompile.pike) which probably is a candidate for 7.8 backport as well but I'll let Grubba weigh in on that.