Unified BitVector Tests

[cdonovick]

There have been and continue to be a number of areas of where [SMT]BitVector and Bits have diverged on the typing of methods and operators. I propose building a unified test sweet which tests the typing of operators that both magma and hwtypes run.

Now I don't want to require that an implementation necessarily have constant propagation or be castable to int so we can't test the values produced. However, the type relationships should be consistent.

Basically I want to make https://github.com/leonardt/hwtypes/blob/master/tests/test_optypes.py more complete and have magma run it as well.