added complex type support

[a-b-h-a-y-s-h-i-n-d-e]

example code:

x: C[3] = [1j, 2j, 3j]

y: C[3] = [1 + 1j, 2 + 2j, 3 + 3j]

z: C[2, 2] = [
    [1 + 2j, 3 + 4j],
    [4 + 9j, 7 + 2j]
]

x
y
z

[JoseAntonioSiguenza]

We need to add complex numbers to type system. Can we add complex number support as an ELF? This way we can introduce type checking rules more easily.