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, 7 insertions, 3 deletions

diff --git a/extmod/moduasyncio.c b/extmod/moduasyncio.c
index 5467642096..b0eb8b6509 100644
--- a/extmod/moduasyncio.c
+++ b/extmod/moduasyncio.c
@@ -287,14 +287,18 @@ STATIC mp_obj_t task_iternext(mp_obj_t self_in) {
     return mp_const_none;
 }
 
+STATIC const mp_getiter_iternext_custom_t task_getiter_iternext = {
+    .getiter = task_getiter,
+    .iternext = task_iternext,
+};
+
 STATIC MP_DEFINE_CONST_OBJ_TYPE(
     task_type,
     MP_QSTR_Task,
-    MP_TYPE_FLAG_NONE,
+    MP_TYPE_FLAG_ITER_IS_CUSTOM,
     task_make_new,
     attr, task_attr,
-    getiter, task_getiter,
-    iternext, task_iternext
+    iter, &task_getiter_iternext
     );
 
 /******************************************************************************/