We add broadcasting support for add, sub, mul and equal.

The broadcasting semantics are specified here
https://numpy.org/doc/stable/user/basics.broadcasting.html

Say we are given input
A (4d array):  8 x 1 x 6 x 1
B (3d array):      7 x 1 x 5

We generate a loop with
Result (4d array):  8 x 7 x 6 x 5
for i0=[0:8]
  for i1=[0:7]
    for i2=[0:6]
      for i3=[0:8]
        Result[i0][i1][i2][i3] = A[i0][0][i2][0] {+,*,-,==} B[i1][0][i3]