fix inspect.formatargspec on functions with keyword-only arguments without defaults #4959
diff --git a/Lib/test/inspect_fodder2.py b/Lib/test/inspect_fodder2.py
index d244935..bd7106f 100644
--- a/Lib/test/inspect_fodder2.py
+++ b/Lib/test/inspect_fodder2.py
@@ -105,3 +105,7 @@
 #line 105
 def annotated(arg1: list):
     pass
+
+#line 109
+def keyword_only_arg(*, arg):
+    pass