SCM_ALRM_SIGNAL, SCM_GC_SIGNAL, SCM_TICK_SIGNAL, SCM_SIG_ORD,
SCM_ORD_SIG, SCM_NUM_SIGS, SCM_SLOPPY_STRINGP, SCM_VALIDATE_STRINGORSUBSTR,
SCM_FREEP, SCM_NFREEP
+- remove scm_vector_set_length_x
- remove function scm_call_catching_errors
(replaced by catch functions from throw.[ch])
- remove support for "#&" reader syntax in (ice-9 optargs).