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()

1 files changed, 15 insertions, 0 deletions

diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 0b7b61d8b1e..515994f0490 100644
--- a/Python/sysmodule.c
+++ b/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)
 {