Layer not rendering correctly when property value's negative

[LukasPaczos]

As seen on the gif, when we are hitting tilt == 60 we are trying to set one of the layer offset values to -3f here via a source property and an expression. The value ends up being casted to uint64_t even though it's a negative value, which I think is the reason why the layer is not rendered correctly. I wasn't able to find the exact point during the rendring proccess when this incorrect cast can cause the layer to diappear entirely instead of rendering the wrong offset though.

/cc @danesfeder @tobrun @alexshalamov