ObjectFIFO unroll algorithm does not unroll newly generated for loops

[AndraBisca]

The unroll algorithm introduced by #1545 may sometimes generated new for loops in order to account for remainder iterations of original input for loops (i.e. when the original loop number of iterations is not a multiple of the unroll factor). However, does newly introduced for loops need to be unrolled as well to achieve functional correctness from the object FIFOs. This is shown in #1716 .