Yes. In my hypothetical world where the C compiler makes use of the VLA declaration in the function arguments, it would certainly be possible for the compiler to insert automatic bounds checking in this case:

  double f(xs, n)
    double xs[n];
    size_t n;
  {
    size_t _tmp0 = g();   /* temporary var created by compiler */
    assert(_tmp0 < n);    /* bounds check inserted by compiler */
    return xs[_tmp0];
  }

The key to making this possible is telling the compiler about the relationship between double* xs and size_t n; once the compiler has the knowledge that the type of xs is double [n] (array of double with first dimension n) it would be able to automatically insert dynamic bounds checks.