Enabled many .cvc llvm-lit tests. CVC4 was used as an oracle for these
tests.

CVC4 could not parse all of the .cvc files so those have not been
enabled and need more investigation.

It's interesting to note that for the
bio-tests/4-alpha-helices-2-rungs-more-bits-simplified.cvc test
CVC4 and STP give different answers.