bpo-39245: Switch to public API for Vectorcall (GH-18460)

The bulk of this patch was generated automatically with:

    for name in \
        PyObject_Vectorcall \
        Py_TPFLAGS_HAVE_VECTORCALL \
        PyObject_VectorcallMethod \
        PyVectorcall_Function \
        PyObject_CallOneArg \
        PyObject_CallMethodNoArgs \
        PyObject_CallMethodOneArg \
    ;
    do
        echo $name
        git grep -lwz _$name | xargs -0 sed -i "s/\b_$name\b/$name/g"
    done

    old=_PyObject_FastCallDict
    new=PyObject_VectorcallDict
    git grep -lwz $old | xargs -0 sed -i "s/\b$old\b/$new/g"

and then cleaned up:

- Revert changes to in docs & news
- Revert changes to backcompat defines in headers
- Nudge misaligned comments

1 files changed, 1 insertions, 1 deletions

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 164104e..8f6ce39 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -2127,7 +2127,7 @@ dict_subscript(PyDictObject *mp, PyObject *key)
             _Py_IDENTIFIER(__missing__);
             missing = _PyObject_LookupSpecial((PyObject *)mp, &PyId___missing__);
             if (missing != NULL) {
-                res = _PyObject_CallOneArg(missing, key);
+                res = PyObject_CallOneArg(missing, key);
                 Py_DECREF(missing);
                 return res;
             }