arnold-usd does not respect all types of visibility

[kreppene]

Describe the bug
it looks like not all kinds of visibility is supported in arnold-usd
i run this check before create any arnold geo in my dev branch, and that seams to do the what we want (stolen from the Rodeofx project)

bool getPrimVisibility(const UsdPrim& prim, float frame)
{
	// We should also consider standard USD visibility flag.
    UsdGeomImageable imageable = UsdGeomImageable(prim);
    bool invisibleFromUSD = imageable &&
        imageable.ComputeVisibility(frame) == UsdGeomTokens->invisible;

    return invisibleFromUSD;
}

To Reproduce
render the .ass file provided

Expected behavior
We expect only 1 sphere to be visible, but 2 is visible when rendering,
theirs a total of 3 spheres inn the scene,
so it looks like it respect some kind visibility but not all

Screenshots

Used Software Versions

• Arnold 6.0.1.0
• USD 0.19.11
• visual studio 2017
• Windows 10

visibility_test.zip