Unreachable reached

[zakarumych]

Message:  internal error: entered unreachable code: Expression [7] is not cached!
Location: ~/.cargo/git/checkouts/naga-dbb2b19faed49210/89bed99/src/back/spv/block.rs:1797

Reproducible with

fn test(rng: ptr<function, u32>) {}

fn woops(uv: vec2<u32>) {
    var rngs = vec3<u32>(1, 2, 3);
    test(&rngs.x);
}