rb_f_exit         257 include/ruby/intern.h VALUE rb_f_exit(int,VALUE*);
rb_f_exit        5030 process.c          rb_define_global_function("exit", rb_f_exit, -1);
rb_f_exit        5050 process.c          rb_define_singleton_method(rb_mProcess, "exit", rb_f_exit, -1);