Make co_argcount for positional-only arguments behave correctly, now that...

Make co_argcount for positional-only arguments behave correctly, now that CPython 3.8 (beta 1) includes the pos-only count in it rather than adding it.

Cython/Utility/ModuleSetupCode.c

@@ -392,13 +392,13 @@ class __Pyx_FakeReference {
 #if PY_MAJOR_VERSION < 3
   #define __Pyx_BUILTIN_MODULE_NAME "__builtin__"
   #define __Pyx_PyCode_New(a, p, k, l, s, f, code, c, n, v, fv, cell, fn, name, fline, lnos) \
-          PyCode_New(p+a+k, l, s, f, code, c, n, v, fv, cell, fn, name, fline, lnos)
+          PyCode_New(a+k, l, s, f, code, c, n, v, fv, cell, fn, name, fline, lnos)
   #define __Pyx_DefaultClassType PyClass_Type
 #else
   #define __Pyx_BUILTIN_MODULE_NAME "builtins"
 #if PY_VERSION_HEX < 0x030800A4
   #define __Pyx_PyCode_New(a, p, k, l, s, f, code, c, n, v, fv, cell, fn, name, fline, lnos) \
-          PyCode_New(p+a, k, l, s, f, code, c, n, v, fv, cell, fn, name, fline, lnos)
+          PyCode_New(a, k, l, s, f, code, c, n, v, fv, cell, fn, name, fline, lnos)
 #else
   #define __Pyx_PyCode_New(a, p, k, l, s, f, code, c, n, v, fv, cell, fn, name, fline, lnos) \
           PyCode_New(a, p, k, l, s, f, code, c, n, v, fv, cell, fn, name, fline, lnos)

tests/run/posonly.py

@@ -78,10 +78,8 @@ def func_introspection1(a, b, c, /, d, e=1, *, f, g=2):
     """
     >>> if sys.version_info[0] < 3:
     ...     assert func_introspection2.__code__.co_argcount == 7, func_introspection2.__code__.co_argcount
-    ... elif sys.version_info < (3, 8):
-    ...     assert func_introspection2.__code__.co_argcount == 5, func_introspection2.__code__.co_argcount
     ... else:
-    ...     assert func_introspection2.__code__.co_argcount == 2, func_introspection2.__code__.co_argcount
+    ...     assert func_introspection2.__code__.co_argcount == 5, func_introspection2.__code__.co_argcount
     >>> func_introspection1.__defaults__
     (1,)
     """
@@ -91,10 +89,8 @@ def func_introspection2(a, b, c=1, /, d=2, e=3, *, f, g=4):
     """
     >>> if sys.version_info[0] < 3:
     ...     assert func_introspection2.__code__.co_argcount == 7, func_introspection2.__code__.co_argcount
-    ... elif sys.version_info < (3, 8):
-    ...     assert func_introspection2.__code__.co_argcount == 5, func_introspection2.__code__.co_argcount
     ... else:
-    ...     assert func_introspection2.__code__.co_argcount == 2, func_introspection2.__code__.co_argcount
+    ...     assert func_introspection2.__code__.co_argcount == 5, func_introspection2.__code__.co_argcount
     >>> func_introspection2.__defaults__
     (1, 2, 3)
     """