Null matrix can always be stacked

[tjstienstra]

While developing in sympy I stumbled upon the difference that within sympy a null matrix can be stacked. The issue within sympy about this problem was #10770.

[tjstienstra]

Not sure, but I also ran into the problem that when using the symengine in python Matrix(0, 1, []).shape == (0, 0), instead of the expected (0, 1).
Currently:

Matrix(1, 0).shape == (1, 0)
Matrix(1, 0, []).shape == (1, 0)
Matrix(0, 1).shape == (0, 1)
Matrix(0, 1, []).shape == (0, 0)