bpo-46417: Finalize structseq types at exit (GH-30645)

Add _PyStructSequence_FiniType() and _PyStaticType_Dealloc()
functions to finalize a structseq static type in Py_Finalize().
Currrently, these functions do nothing if Python is built in release
mode.

Clear static types:

* AsyncGenHooksType: sys.set_asyncgen_hooks()
* FlagsType: sys.flags
* FloatInfoType: sys.float_info
* Hash_InfoType: sys.hash_info
* Int_InfoType: sys.int_info
* ThreadInfoType: sys.thread_info
* UnraisableHookArgsType: sys.unraisablehook
* VersionInfoType: sys.version
* WindowsVersionType: sys.getwindowsversion()

Python/errors.c

@@ -1241,6 +1241,17 @@ _PyErr_InitTypes(PyInterpreterState *interp)
 }
 
 
+void
+_PyErr_FiniTypes(PyInterpreterState *interp)
+{
+    if (!_Py_IsMainInterpreter(interp)) {
+        return;
+    }
+
+    _PyStructSequence_FiniType(&UnraisableHookArgsType);
+}
+
+
 static PyObject *
 make_unraisable_hook_args(PyThreadState *tstate, PyObject *exc_type,
                           PyObject *exc_value, PyObject *exc_tb,

Python/pylifecycle.c

@@ -1666,11 +1666,17 @@ flush_std_files(void)
 static void
 finalize_interp_types(PyInterpreterState *interp)
 {
+    _PySys_Fini(interp);
     _PyExc_Fini(interp);
     _PyFrame_Fini(interp);
     _PyAsyncGen_Fini(interp);
     _PyContext_Fini(interp);
+    _PyFloat_FiniType(interp);
+    _PyLong_FiniTypes(interp);
+    _PyThread_FiniType(interp);
+    _PyErr_FiniTypes(interp);
     _PyTypes_Fini(interp);
+
     // Call _PyUnicode_ClearInterned() before _PyDict_Fini() since it uses
     // a dict internally.
     _PyUnicode_ClearInterned(interp);

Python/sysmodule.c

@@ -3102,6 +3102,21 @@ error:
 }
 
 
+void
+_PySys_Fini(PyInterpreterState *interp)
+{
+    if (_Py_IsMainInterpreter(interp)) {
+        _PyStructSequence_FiniType(&VersionInfoType);
+        _PyStructSequence_FiniType(&FlagsType);
+#if defined(MS_WINDOWS)
+        _PyStructSequence_FiniType(&WindowsVersionType);
+#endif
+        _PyStructSequence_FiniType(&Hash_InfoType);
+        _PyStructSequence_FiniType(&AsyncGenHooksType);
+    }
+}
+
+
 static PyObject *
 makepathobject(const wchar_t *path, wchar_t delim)
 {

Python/thread.c

@@ -243,3 +243,14 @@ PyThread_GetInfo(void)
     PyStructSequence_SET_ITEM(threadinfo, pos++, value);
     return threadinfo;
 }
+
+
+void
+_PyThread_FiniType(PyInterpreterState *interp)
+{
+    if (!_Py_IsMainInterpreter(interp)) {
+        return;
+    }
+
+    _PyStructSequence_FiniType(&ThreadInfoType);
+}