gh-94936: C getters: co_varnames, co_cellvars, co_freevars (GH-95008)

(cherry picked from commit 42b102bbf9)

Co-authored-by: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>

Objects/codeobject.c

@@ -1399,18 +1399,36 @@ _PyCode_GetVarnames(PyCodeObject *co)
     return get_localsplus_names(co, CO_FAST_LOCAL, co->co_nlocals);
 }
 
+PyObject *
+PyCode_GetVarnames(PyCodeObject *code)
+{
+    return _PyCode_GetVarnames(code);
+}
+
 PyObject *
 _PyCode_GetCellvars(PyCodeObject *co)
 {
     return get_localsplus_names(co, CO_FAST_CELL, co->co_ncellvars);
 }
 
+PyObject *
+PyCode_GetCellvars(PyCodeObject *code)
+{
+    return _PyCode_GetCellvars(code);
+}
+
 PyObject *
 _PyCode_GetFreevars(PyCodeObject *co)
 {
     return get_localsplus_names(co, CO_FAST_FREE, co->co_nfreevars);
 }
 
+PyObject *
+PyCode_GetFreevars(PyCodeObject *code)
+{
+    return _PyCode_GetFreevars(code);
+}
+
 static void
 deopt_code(_Py_CODEUNIT *instructions, Py_ssize_t len)
 {