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/funcobject.c b/Objects/funcobject.c
index ebe68adc336..419db33602a 100644
--- a/Objects/funcobject.c
+++ b/Objects/funcobject.c
@@ -654,7 +654,7 @@ PyTypeObject PyFunction_Type = {
     0,                                          /* tp_setattro */
     0,                                          /* tp_as_buffer */
     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
-    _Py_TPFLAGS_HAVE_VECTORCALL |
+    Py_TPFLAGS_HAVE_VECTORCALL |
     Py_TPFLAGS_METHOD_DESCRIPTOR,               /* tp_flags */
     func_new__doc__,                            /* tp_doc */
     (traverseproc)func_traverse,                /* tp_traverse */