[mypyc] Remove the unused CPyList_GetItemUnsafe primitive (#19424)

We now generate low-level IR directly instead of calling a primitive
function.

Author: JukkaL

mypyc/lib-rt/CPy.h

@@ -646,7 +646,6 @@ PyObject *CPyObject_GetSlice(PyObject *obj, CPyTagged start, CPyTagged end);
 
 PyObject *CPyList_Build(Py_ssize_t len, ...);
 PyObject *CPyList_GetItem(PyObject *list, CPyTagged index);
-PyObject *CPyList_GetItemUnsafe(PyObject *list, CPyTagged index);
 PyObject *CPyList_GetItemShort(PyObject *list, CPyTagged index);
 PyObject *CPyList_GetItemBorrow(PyObject *list, CPyTagged index);
 PyObject *CPyList_GetItemShortBorrow(PyObject *list, CPyTagged index);

mypyc/lib-rt/list_ops.c

@@ -59,14 +59,6 @@ PyObject *CPyList_Copy(PyObject *list) {
     return PyObject_CallMethodNoArgs(list, name);
 }
 
-
-PyObject *CPyList_GetItemUnsafe(PyObject *list, CPyTagged index) {
-    Py_ssize_t n = CPyTagged_ShortAsSsize_t(index);
-    PyObject *result = PyList_GET_ITEM(list, n);
-    Py_INCREF(result);
-    return result;
-}
-
 PyObject *CPyList_GetItemShort(PyObject *list, CPyTagged index) {
     Py_ssize_t n = CPyTagged_ShortAsSsize_t(index);
     Py_ssize_t size = PyList_GET_SIZE(list);