fix signature introspection for functions with kwonly arguments

CHANGES.rst

@@ -11,6 +11,9 @@ Features added
 Bugs fixed
 ----------
 
+* Local variables were erroneously appended to the signature introspection
+  of Cython implemented functions with keyword-only arguments.
+
 * List/Tuple literals multiplied by more than one factor were only multiplied
   by the last factor instead of all.
 

Cython/Compiler/ExprNodes.py

@@ -7643,7 +7643,7 @@ class CodeObjectNode(ExprNode):
 
         code.putln("%s = (PyObject*)__Pyx_PyCode_New(%d, %d, %d, 0, 0, %s, %s, %s, %s, %s, %s, %s, %s, %d, %s); %s" % (
             self.result_code,
-            len(func.args),            # argcount
+            len(func.args) - func.num_kwonly_args,  # argcount
             func.num_kwonly_args,      # kwonlyargcount (Py3 only)
             len(self.varnames.args),   # nlocals
             Naming.empty_bytes,        # code