The definitions added in #299 cause a regression in Prelude typechecking
performance. Until we sort out the performance, we'll keep these
definitions in the module `Cryptol::Extras`.
The `random` primitive previously took a `[32]` seed, but this causes
inconsistency between 32-bit and 64-bit platforms when the seed is large
enough to wrap around in GHC's representation of an `Int`. This patch
switches to an API that seeds directly with four 64-bit words, and so
should behave the same way on our supported platforms.
Implication (==>), not, and, or, all, any, map, foldl, sum, scanl, extend,
extendSigned, foldr, scanr, zip, zipWith, repeat, curry, uncurry, and elem.
Rationale:
I've had to implement these functions several times for different problems.
While my problems were admittedly toy, not cryptographic, the functions are
generally applicable and unlikely to clash with many, if any, preexisting
operations of different semantic meaning.
