rb_make_internal_id 2043 error.c            id_iseq = rb_make_internal_id();
rb_make_internal_id   34 ext/-test-/marshal/internal_ivar/internal_ivar.c     id_internal_ivar = rb_make_internal_id();
rb_make_internal_id 1232 internal.h     ID rb_make_internal_id(void);
rb_make_internal_id 2059 pack.c             id_associated = rb_make_internal_id();