e7eee7764a
This commit brings back motion path calculations working on same level as 2.7x. Caveats: * You cannot actually see anything, as all the drawing code for motion paths was removed and not reimplmented in 2.8 draw engines yet * This doesn't actually use a separate depsgraph instance for fast background calculations yet. That's a separate topic, and will require further investigation (probably after code quest, according to original planning). * The work here *does* however pave the path forwards towards fully separate COW evaluation though. We only need to stub in a different depsgraph instance here to get things working.