Cannot unroll strided loop

[tissue3]

Stride loop can be achieve with suffix, but it is fake. If one wants to unroll that loop, it is not going to work (because of view). In the example of stencil3d, we actually might want to access org[i] and org[i+2] and do this to all three dimensions of matrix org, but we cannot create unroll the loop at all... https://github.com/cucapra/fuse-benchmarks-sdaccel/blob/master/experiments/dahlia-dse/machsuite-stencil-stencil3d-inner/stencil.fuse