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`.
diff --git a/py/repl.c b/py/repl.c
index de0e8a4..7bd8759 100644
--- a/py/repl.c
+++ b/py/repl.c
@@ -57,6 +57,9 @@
|| str_startswith_word(input, "with")
|| str_startswith_word(input, "def")
|| str_startswith_word(input, "class")
+ #if MICROPY_PY_ASYNC_AWAIT
+ || str_startswith_word(input, "async")
+ #endif
;
// check for unmatched open bracket, quote or escape quote