Violated assert: type_is_valid_for_vector(vector_type)

```c
struct Foo { void* x; }

fn void main()
{
  Foo* foo;
  float[<2>] a = foo[0..1];
}
```

```
⚠️ The compiler encountered an unexpected error: "Violated assert: type_is_valid_for_vector(vector_type)".
```