Multidimensional zippering thwarts GPU transformations

[e-kayrakli]

on here.gpus[0] {
  var D = {1..10, 1..10};
  var A: [D] int;
  @assertOnGpu
  foreach (a,i) in zip(A,D) {
    A[i] = a;
  }

  writeln(A);
}

Fails because of assertOnGpu. It looks like there is some kind of dynamic memory allocation for non-inlined, multidimensional iterators. I don't have a good idea as to what that is or whether there's a bandaid without trying to inline multidimensional zippering.

Note that:

• Multidimensional zippering is not great for performance in general: Multidimensional zippered iteration (or promotion) kills performance #13147
• Multidimensional iteration (without zippering) also has potential pitfalls for performance: Multidimensional loops perform poorly as GPU kernels #24331