x86_64 is used as a baseline: the "x86_64" entry, whatever status it has,
is transformed into "all", and then the other entries in ARCHITECTURES
either dropped or rearranged appropriately.
nhc is an Haskell compiler which is easily bootstrappable from C (unlike
ghc). The downsides are:
- It's slower
- It only implements Haskell 98
It may be usable to build GHC or some other Haskell based software,
we'll see.
