Const generic arithmetic in array types not evaluated during unification

[micahscopes]

Array types using const arithmetic like [T; N + 1] parse and check fine in the struct definition, but fail when instantiated because (1 + 1) isn't reduced to 2 for type matching.

struct G1 {
    pub x: u256,
    pub y: u256,
}

struct Vk<const N: usize> {
    pub ic: [G1; N + 1],
}

fn make_vk() -> Vk<1> {
    Vk {
        ic: [G1 { x: 3, y: 4 }, G1 { x: 5, y: 6 }],
    }
}

error: expected `[G1; (1 + 1)]`, but `[G1; 2]` is given