bpo-46541: Remove usage of _Py_IDENTIFIER from mmap module (GH-31375)

Author: corona10

Modules/mmapmodule.c

@@ -21,7 +21,6 @@
 #ifndef Py_BUILD_CORE_BUILTIN
 #  define Py_BUILD_CORE_MODULE 1
 #endif
-#define NEEDS_PY_IDENTIFIER
 
 #define PY_SSIZE_T_CLEAN
 #include <Python.h>
@@ -771,9 +770,7 @@ mmap__enter__method(mmap_object *self, PyObject *args)
 static PyObject *
 mmap__exit__method(PyObject *self, PyObject *args)
 {
-    _Py_IDENTIFIER(close);
-
-    return _PyObject_CallMethodIdNoArgs(self, &PyId_close);
+    return mmap_close_method((mmap_object *)self, NULL);
 }
 
 static PyObject *