emulator: regress without optimization, bench with
Flite: Fix the C backend

Example usage:

   $ cd programs
   $ ../flite/dist/build/Flite/flite -c Queens2.hs > Queens2.c
   $ cc -DPRINT_RESULT -O Queens2.c -o Queens2
   $ ./Queens2
   2680

Much could be done to improve the performance of the generated C code.