patch applied (ghc): replace Cmm 'hint' with 'kind'

[Norman Ramsey]

 > this place seems to allude to "hints" as well as the hacky tuple that I
 > think is the one I fixed by turning it into a data type (so it could be put
 > into typeclasses reasonably), but maybe isn't up-to-date, and doesn't
 > explain it:
 > http://hackage.haskell.org/trac/ghc/wiki/Commentary/Compiler/BackEndTypes#Foreigncallsandhints

Hmmm.  I found myself baffled by much of this text.
I suspect that to fix it may take the combined efforts of multiple people.

We have a virtual meeting of back-end boffins scheduled for this week.


Norman