implement tests from "Finding Bugs in Cryptographic Hash Function Implementations"

[mmcloughlin]

@dgryski suggested the paper "Finding Bugs in Cryptographic Hash Function Implementations", by Nicky Mouha and Mohammad S Raunak and D. Richard Kuhn and Raghu Kacker https://eprint.iacr.org/2017/891

It would be worth implementing some of the tests here:

• "Bit-Contribution Test" verifies that flipping all bits of various sized messages produces unique results
• "Bit-Exclusion Test" modifies bits after the end of the buffer, to confirm there are no out-of-bounds reads affecting the result. This could affect Go assembly implementations, without the safety of bounds checking.
• "Update Test" and "Combinatorial Update Test" test chunking behavior. I believe we have this covered in the fuzzers already.
• The paper also references an "Extremely Large Message Test" which is covered by feed large inputs to fuzz functions #15

Not clear if this belongs in this repo or not. Possible candidates for x/crypto/cryptotest.