This also requires implementing the corresponding matrix (NMatrix4x3).
Fixes this xtro issue:
> !unknown-simd-type-in-signature! OpenTK.Matrix3 AVFoundation.AVCameraCalibrationData::get_GetIntrinsicMatrix(): the native signature has a simd type (matrix_float3x3), while the corresponding managed method is using an incorrect (non-simd) type.
Rolf Bjarne Kvinge