tests

This commit does a few things at once:

- Updates the tests to contain the latest data from ethereum/tests repo.
- Enables Constantinople state tests. This is needed to be able to
  fuzz-test the evm with constantinople rules.
- Fixes the error in opSAR that we've known about for some time. I was
  kind of saving it to see if we hit upon it with the random test
  generator, but it's difficult to both enable the tests and have the
  bug there -- we don't want to forget about it, so maybe it's better
  to just fix it.