bpo-36974: separate vectorcall functions for each calling convention (GH-13781)

diff --git a/Lib/test/test_call.py b/Lib/test/test_call.py
index b252ca1..0bff7de 100644
--- a/Lib/test/test_call.py
+++ b/Lib/test/test_call.py
@@ -586,6 +586,8 @@
                 return super().__call__(*args)
 
         calls += [
+            (dict.update, ({},), {"key":True}, None),
+            ({}.update, ({},), {"key":True}, None),
             (MethodDescriptorHeap(), (0,), {}, True),
             (MethodDescriptorOverridden(), (0,), {}, 'new'),
             (MethodDescriptorSuper(), (0,), {}, True),