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, 2 insertions, 2 deletions

diff --git a/Objects/memoryobject.c b/Objects/memoryobject.c
index d9dd117..906d1ce 100644
--- a/Objects/memoryobject.c
+++ b/Objects/memoryobject.c
@@ -1963,7 +1963,7 @@ struct_get_unpacker(const char *fmt, Py_ssize_t itemsize)
     if (format == NULL)
         goto error;
 
-    structobj = _PyObject_CallOneArg(Struct, format);
+    structobj = PyObject_CallOneArg(Struct, format);
     if (structobj == NULL)
         goto error;
 
@@ -2002,7 +2002,7 @@ struct_unpack_single(const char *ptr, struct unpacker *x)
     PyObject *v;
 
     memcpy(x->item, ptr, x->itemsize);
-    v = _PyObject_CallOneArg(x->unpack_from, x->mview);
+    v = PyObject_CallOneArg(x->unpack_from, x->mview);
     if (v == NULL)
         return NULL;