For what it is worth...FakeAOGPU works for me in 64-bit v17 both as a render time post effect and as a post effect in a Composite
However, both FakeAOGPU and FakeAOCPU crash my 32-bit v17
One other work-around for people who want to use 32-bit v17 but also want to have FakeAO....
Render without FakeAO in V17 to OpenEXR with a depth buffer, then use that OpenEXR file in a Composite in v16 to add the FakeAO as a Post effect.
Of course this is more efficient for image sequences than single images, but if you tend to use FakeAO in Post anyway, like me, it's a minor commute.