Patch #1680961: remove sys.exitfunc and replace it with a private C API. Also, reimplement atexit in C so it can take advantage of this private API.
diff --git a/Python/import.c b/Python/import.c
index 33953c7..6d65703 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -361,7 +361,7 @@
/* List of names to clear in sys */
static char* sys_deletes[] = {
- "path", "argv", "ps1", "ps2", "exitfunc",
+ "path", "argv", "ps1", "ps2",
"exc_type", "exc_value", "exc_traceback",
"last_type", "last_value", "last_traceback",
"path_hooks", "path_importer_cache", "meta_path",