.view() for NumPy types broken if the view type is a complex type

[stuartarchibald]

Reporting a bug

• I have tried using the latest released version of Numba (most recent is
  visible in the change log (https://github.com/numba/numba/blob/master/CHANGE_LOG).
• I have included a self contained code sample to reproduce the problem.
  i.e. it's possible to run as 'python bug.py'.

This:

from numba import njit
import numpy as np

@njit
def foo(x):
    return x.view(np.complex64)

foo(1)

does:

cpython/unsafe/numbers.py", line 18, in viewer
                      assert 0, "unreachable"
                  AssertionError: unreachable