Implement PEP 380 - 'yield from' (closes #11682)
diff --git a/Parser/Python.asdl b/Parser/Python.asdl
index 6955199..8ae4e59 100644
--- a/Parser/Python.asdl
+++ b/Parser/Python.asdl
@@ -59,7 +59,7 @@
 	     | DictComp(expr key, expr value, comprehension* generators)
 	     | GeneratorExp(expr elt, comprehension* generators)
 	     -- the grammar constrains where yield expressions can occur
-	     | Yield(expr? value)
+	     | Yield(int is_from, expr? value)
 	     -- need sequences for compare to distinguish between
 	     -- x < 4 < 3 and (x < 4) < 3
 	     | Compare(expr left, cmpop* ops, expr* comparators)