BoundsError with simple model

[alhirzel]

I found this when trying to create the MNWE for #90. When executing the following model, a BoundsError results.

using Modia

@model OutOfBounds begin
    dummy = Var(size=(2,))
    @equations begin
        0 = 1
        1 = 2
    end
end

res = simulate(OutOfBounds, -1000; removeSingularities=false);

Ideally, an error message would be shown that indicates the dummy variables are unassigned, or perhaps even that nonsensical equations are present.