Added instructions to teach souper about undefined behavior and also add...

...ed test cases

- This patch has support for all instructions UB
- Test cases integrated in LIT infrastructure
- Fix to set solver path via command line by John
Right.

Jubi: as I was saying last time we met, for each new feature that you added, you should try to have a positive and a negative test. Peter's suggestion is a good positive test and the same test case without "nsw" would be the obvious corresponding negative test.