Jiwon Seo's PEP 3102 implementation.
See SF#1549670.
The compiler package has not yet been updated.
diff --git a/Parser/Python.asdl b/Parser/Python.asdl
index b62197e..dbf14e7 100644
--- a/Parser/Python.asdl
+++ b/Parser/Python.asdl
@@ -100,8 +100,8 @@
 	excepthandler = (expr? type, expr? name, stmt* body, int lineno,
 	                 int col_offset)
 
-	arguments = (expr* args, identifier? vararg, 
-		     identifier? kwarg, expr* defaults)
+	arguments = (expr* args, identifier? vararg, expr* kwonlyargs,
+		         identifier? kwarg, expr* defaults, expr* kw_defaults)
 
         -- keyword arguments supplied to call
         keyword = (identifier arg, expr value)