remove "simplify_recursive_definition", never used

Makefile.in

drivers/alt_ergo_bare.drv

drivers/alt_ergo_smt2.drv

drivers/coq-common.gen

drivers/cvc3_bare.drv

drivers/cvc4_bare.drv

drivers/gappa.drv

drivers/mathematica.drv

drivers/mathsat.drv

drivers/pvs-common.gen

drivers/simplify.drv

drivers/spass_types.drv

drivers/tptp-tff.drv

drivers/tptp.gen

drivers/verit.drv

drivers/yices_bare.drv

drivers/z3_bare.drv

drivers/z3_smtv1.drv

drivers/zenon.drv

src/transform/simplify_recursive_definition.ml