For internal spidr use only.
data ShapeIndex : Type
MkShapeIndex : GCAnyPtr -> ShapeIndex
delete : HasIO io => AnyPtr -> io ()
allocShapeIndex : HasIO io => io ShapeIndex
pushBack : HasIO io => ShapeIndex -> Nat -> io ()
pushFront : HasIO io => ShapeIndex -> Nat -> io ()
mkShape : (HasIO io, Primitive dtype) => Shape -> io Shape