implement c-get/c-set prims.
implement c-get/c-set prims.

irken-type->c-type: complete the decode-name table.
s/c-pref/c-get-ptr: matches other names.

c-set/c-get: an experiment that almost worked, to be removed.
  [wasn't possible to collapse pointer and integer references
   with type inference].
Instead, we have two sets of cref prims: c-get-int/c-set-int, and
  c-get-ptr/c-set-ptr.

samrushing/irken-compiler,samrushing/irken-compiler,samrushing/irken-compiler,samrushing/irken-compiler