Removes shuffle operations running back to back when their modes are reciplocal.

Example:

c = shuffle(a, b, interleave_T128_4x2_lo)
d = shuffle(a, b, interleave_T128_4x2_hi)
 
e = shuffle(c, d, interleave_T128_2x4_lo)
f = shuffle(c, d, interleave_T128_2x4_hi)

e = a;

f = b;