vm types

I believe the following code is not producing the expected result or diagnostics.

```c
void f(int n, int m, int a[n][m])
{
}

int main()
{
    int a[2][3] ={
        1, 2, 3,
        4, 5, 6
    };
    f(2, 3, a);
    return 0;
}


```
