These changes are necessary. Need to mark vertices of edges passed
in geom; also the normals.out slot has a custom element type, not
ELEM, so need to prevent attempt by python code to convert it to
an elem. But this leaves a memory leak. I will rework code to not
use normals.out slot at all, but that's a bigger fix.
Now there is a crash in a different place (GPU code). Think that if
using Op on its own (instead of from edbm_bevel_calc, there needs to
be a dependency graph update and maybe more?