v3d: support for interpolateAt
Those two commits initially included on !6766 (merged), already have Rb/Ack, but left one while !6721 (merged) was being reviewed (as the patches were based on them). Let's merge them now.
Those two commits initially included on !6766 (merged), already have Rb/Ack, but left one while !6721 (merged) was being reviewed (as the patches were based on them). Let's merge them now.