- missing DECREF in PyModule_FromDefAndSpec2
- missing DECREF in PyType_FromSpecAndBases2
- missing DECREF in _testmultiphase module

Patch by Petr Viktorin

Known limitations of the current implementation:

- documentation changes are incomplete
- there's a reference leak I haven't tracked down yet

The leak is most visible by running:

  ./python -m test -R3:3 test_importlib

However, you can also see it by running:

  ./python -X showrefcount

Importing the array or _testmultiphase modules, and
then deleting them from both sys.modules and the local
namespace shows significant increases in the total
number of active references each cycle. By contrast,
with _testcapi (which continues to use single-phase
initialisation) the global refcounts stabilise after
a couple of cycles.

Raise PendingDeprecationWarning when generator raises StopIteration
and no __future__ import is used.  Fix offenders in the stdlib
and tests.

See also issue 22906.
Thanks to Nick Coghlan and Berker Peksag for reviews.

Fixed segmentation fault in sqlite3.Row constructor with faked cursor type.
Fixed system error in the comparison of faked types.SimpleNamespace.

Fixed segmentation fault in sqlite3.Row constructor with faked cursor type.
Fixed system error in the comparison of faked types.SimpleNamespace.

Clement Rouault.

Clement Rouault.

Patch by Martin Panter.