Andesite slabs to polished andesite slabs

I've noticed while working on my road designs, that there is no way to change andesite slabs into their polished variant, which is weird, because 1 andesite is 1 polished andesite. it should simply be implemented that 4 andesite slabs in a square should give 4 polished andesite slabs. the stonecutter should also just polish the slabs. pretty simple.