speed up cythonized hexiom2 benchmark a little by using C int arrays instead of fixed size Python lists

--HG--
extra : amend_source : c0a1e78dbfd443585a80bd646b763617eeb6b7c5

allow list literals with a constant multiplier to be assigned to C arrays, extend array assignment tests

This seems to have been a mis-understanding on how C++ works/is wrapped.

prevent recursively generated Cython utility code (i.e. used by other Cython utility code) from appearing multiple times in the output due to a different outer module scope

--HG--
rename : Cython/Utility/CFuncConvert.pyx => Cython/Utility/CConvert.pyx