Cast function pointers to (void(*)(void)) before casting to (PyCFunction)
to make "warning: cast between incompatible function types" false alarm quiet.
* bpo-32492: 2.5x speed up in namedtuple attribute access using C fast path
* Add News entry
* fixup! bpo-32492: 2.5x speed up in namedtuple attribute access using C fast path
* Check for tuple in the __get__ of the new descriptor and don't cache the descriptor itself
* Don't inherit from property. Implement GC methods to handle __doc__
* Add a test for the docstring substitution in descriptors
* Update NEWS entry to reflect time against 3.7 branch
* Simplify implementation with argument clinic, better error messages, only __new__
* Use positional-only parameters for the __new__
* Use PyTuple_GET_SIZE and PyTuple_GET_ITEM to tighter the implementation of tuplegetterdescr_get
* Implement __set__ to make tuplegetter a data descriptor
* Use Py_INCREF now that we inline PyTuple_GetItem
* Apply the valid_index() function, saving one test
* Move Py_None test out of the critical path.
Fix invalid function cast warnings with gcc 8
for method conventions different from METH_NOARGS, METH_O and
METH_VARARGS excluding Argument Clinic generated code.
METH_NOARGS functions need only a single argument but they are cast
into a PyCFunction, which takes two arguments. This triggers an
invalid function cast warning in gcc8 due to the argument mismatch.
Fix this by adding a dummy unused argument.
