bpo-44114: Fix dictkeys_reversed and dictvalues_reversed function sig…

…natures (GH-26062)

These are passed and called as PyCFunction, however they are defined here without the (ignored) args parameter.

This works fine in some C compilers, but fails in webassembly or anything else that has strict function pointer call type checking.

Misc/NEWS.d/next/Core and Builtins/2021-05-12-14-26-16.bpo-44114.p-WfAE.rst

@@ -0,0 +1 @@
+Fix incorrect dictkeys_reversed and dictitems_reversed function signatures in C code, which broke webassembly builds.

Objects/dictobject.c

@@ -4826,7 +4826,7 @@ static PySequenceMethods dictitems_as_sequence = {
     (objobjproc)dictitems_contains,     /* sq_contains */
 };
 
-static PyObject* dictitems_reversed(_PyDictViewObject *dv);
+static PyObject* dictitems_reversed(_PyDictViewObject *dv, PyObject *Py_UNUSED(ignored));
 
 PyDoc_STRVAR(reversed_items_doc,
 "Return a reverse iterator over the dict items.");
@@ -4879,7 +4879,7 @@ dictitems_new(PyObject *dict, PyObject *Py_UNUSED(ignored))
 }
 
 static PyObject *
-dictitems_reversed(_PyDictViewObject *dv)
+dictitems_reversed(_PyDictViewObject *dv, PyObject *Py_UNUSED(ignored))
 {
     if (dv->dv_dict == NULL) {
         Py_RETURN_NONE;
@@ -4909,7 +4909,7 @@ static PySequenceMethods dictvalues_as_sequence = {
     (objobjproc)0,                      /* sq_contains */
 };
 
-static PyObject* dictvalues_reversed(_PyDictViewObject *dv);
+static PyObject* dictvalues_reversed(_PyDictViewObject *dv, PyObject *Py_UNUSED(ignored));
 
 PyDoc_STRVAR(reversed_values_doc,
 "Return a reverse iterator over the dict values.");
@@ -4960,7 +4960,7 @@ dictvalues_new(PyObject *dict, PyObject *Py_UNUSED(ignored))
 }
 
 static PyObject *
-dictvalues_reversed(_PyDictViewObject *dv)
+dictvalues_reversed(_PyDictViewObject *dv, PyObject *Py_UNUSED(ignored))
 {
     if (dv->dv_dict == NULL) {
         Py_RETURN_NONE;