o Minor bugfixes (compilation):
    - Compile the ed25519-donna code with a correct declaration of
      crypto_strongest_rand(). Previously, we build it with one type,
      but link it against another in the unit tests, which caused
      compilation failures with LTO enabled, and which could have
      caused other undefined behavior in the tests. Fixes bug 27728;
      bugfix on 0.3.5.1-alpha.