* module/language/cps2/optimize.scm: New file.
* module/language/cps2/simplify.scm: New file, factored out of
simplify2.scm.
* module/language/cps/simplify2.scm: Remove, as it's obsolete.
* module/language/cps2/compile-cps.scm: Optimize the CPS.
* module/Makefile.am: Adapt for added and deleted files.
