This change adds the necessary items to the build projects to avoid erroring out right at the start. It does not add _support_ for targeting Windows on ARM32, but is a necessary prerequisite for adding it.

Fix a crash in slice_richcompare(): use strong references rather than
stolen references for the two temporary internal tuples.

The crash (or assertion error) occurred if a garbage collection
occurred during slice_richcompare(), especially while calling
PyObject_RichCompare(t1, t2, op).

Minor code clean-up.

Make test_imap4_host_default_value independent on whether the 
local IMAP server is running.

bpo-35972: _xxsubinterpreters: Fix potential integer truncation on 32-bit in channel_send() (gh-11822)

Changes in this commit:

1. Use a _strong_ reference between the Pool and associated iterators
2. Rework PR #8450 to eliminate a cycle in the Pool.

There is no test in this commit because any test that automatically tests this behaviour needs to eliminate the pool before joining the pool to check that the pool object is garbaged collected/does not hang. But doing this will potentially leak threads and processes (see https://bugs.python.org/issue35413).

If PyUnicode_DecodeUTF8() returns NULL, PyArena_AddPyObject() would crash.
Found by @msullivan for https://github.com/python/typed_ast/pull/93.

Original patch by Mike Short


https://bugs.python.org/issue22062

Keeping references to processes and managers between tests makes them count as dangling processes.

Add  a code example block.

Add tooling that will useful in future updates, paying particular attention to difficult cases where only the upper bits on the input vary.

Use autoconfig to probe for shm_open() and shm_unlink().  Set SHM_NEEDS_LIBRT if we must
link with librt to get the shm_* functions.  Change setup.py to use the autoconfig defines.  These
changes should make it more likely that _multiprocessing/posixshmem.c gets built correctly on
different platforms.

This was a backwards incompatible change and should be clearly noted.

Related bugs:

bpo-32417: https://bugs.python.org/issue32417
bpo-35364: https://bugs.python.org/issue35364

Protect dict iterations by wrapping them with _IterationGuard in the
following methods:

- WeakValueDictionary.copy()
- WeakValueDictionary.__deepcopy__()
- WeakKeyDictionary.copy()
- WeakKeyDictionary.__deepcopy__()

Add a cell constructor, expose the cell type in the types module.

bpo-24209: In http.server script, rely on getaddrinfo to bind to preferred address based on the bind parameter. (#11767)

In http.server script, rely on getaddrinfo to bind to preferred address based on the bind parameter.

As a result, now IPv6 is used as the default (including IPv4 on dual-stack systems). Enhanced tests.

multiprocessing: provide unittests for manager classes and shareable types