py/obj: Merge getiter and iternext mp_obj_type_t slots.

The goal here is to remove a slot (making way to turn make_new into a slot)
as well as reduce code size by the ~40 references to mp_identity_getiter
and mp_stream_unbuffered_iter.

This introduces two new type flags:
- MP_TYPE_FLAG_ITER_IS_ITERNEXT: This means that the "iter" slot in the
  type is "iternext", and should use the identity getiter.
- MP_TYPE_FLAG_ITER_IS_CUSTOM: This means that the "iter" slot is a pointer
  to a mp_getiter_iternext_custom_t instance, which then defines both
  getiter and iternext.

And a third flag that is the OR of both, MP_TYPE_FLAG_ITER_IS_STREAM: This
means that the type should use the identity getiter, and
mp_stream_unbuffered_iter as iternext.

Finally, MP_TYPE_FLAG_ITER_IS_GETITER is defined as a no-op flag to give
the default case where "iter" is "getiter".

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/py/obj.c b/py/obj.c
index 359c73b9c..eb17308fe 100644
--- a/py/obj.c
+++ b/py/obj.c
@@ -572,10 +572,10 @@ mp_obj_t mp_identity(mp_obj_t self) {
 }
 MP_DEFINE_CONST_FUN_OBJ_1(mp_identity_obj, mp_identity);
 
-mp_obj_t mp_identity_getiter(mp_obj_t self, mp_obj_iter_buf_t *iter_buf) {
-    (void)iter_buf;
-    return self;
-}
+// mp_obj_t mp_identity_getiter(mp_obj_t self, mp_obj_iter_buf_t *iter_buf) {
+//     (void)iter_buf;
+//     return self;
+// }
 
 bool mp_get_buffer(mp_obj_t obj, mp_buffer_info_t *bufinfo, mp_uint_t flags) {
     const mp_obj_type_t *type = mp_obj_get_type(obj);