py: add async/await/async for/async with syntax

They are sugar for marking function as generator, "yield from"
and pep492 python "semantically equivalents" respectively.

@dpgeorge was the original author of this patch, but @pohmelie made
changes to implement `async for` and `async with`.

1 files changed, 1 insertions, 0 deletions

diff --git a/py/obj.h b/py/obj.h
index 25f31ea5a..809acb5a3 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -561,6 +561,7 @@ extern const mp_obj_type_t mp_type_OSError;
 extern const mp_obj_type_t mp_type_TimeoutError;
 extern const mp_obj_type_t mp_type_OverflowError;
 extern const mp_obj_type_t mp_type_RuntimeError;
+extern const mp_obj_type_t mp_type_StopAsyncIteration;
 extern const mp_obj_type_t mp_type_StopIteration;
 extern const mp_obj_type_t mp_type_SyntaxError;
 extern const mp_obj_type_t mp_type_SystemExit;