closes bpo-35643: Fix a SyntaxWarning: invalid escape sequence in Modules/_sha3/cleanup.py (GH-11411)

Revert "bpo-35603: Escape table header of make_table output that can cause potential XSS. (GH-11341)" (GH-11356)

This reverts commit 78de0119.

* bpo-35588: Implement mod and divmod operations for Fraction type by spelling out the numerator/denominator calculation, instead of instantiating and normalising Fractions along the way. This speeds up '%' and divmod() by 2-3x.

* bpo-35588: Also reimplement Fraction.__floordiv__() using integer operations to make it ~4x faster.

* Improve code formatting.
Co-Authored-By: scoder <stefan_ml@behnel.de>

* bpo-35588: Fix return type of divmod(): the result of the integer division should be an integer.

* bpo-35588: Further specialise __mod__() and inline the original helper function _flat_divmod() since it's no longer reused.

* bpo-35588: Add some tests with large numerators and/or denominators.

* bpo-35588: Use builtin "divmod()" function for implementing __divmod__() in order to simplify the implementation, even though performance results are mixed.

* Rremove accidentally added empty line.

* bpo-35588: Try to provide more informative output on test failures.

* bpo-35588: Improve wording in News entry.
Co-Authored-By: scoder <stefan_ml@behnel.de>

* Remove stray space.

_Py_HashBytes() does the check for empty string.

There is already a `Py_ssize_t i` defined at function scope that is used
for similar loops. By removing the local `int i` declaration that `i` is
used, which has the appropriate type.

Move translate_key() and constant tuples to module level.
Inline the remnant one-line function.

* Replace the docstrings cache with sys.intern().
* Improve tests.
* Unify names of tp_descr_get and tp_descr_set functions.

A minor typo in the output of `python -m test -h`.
A space was missing in between two words.
howmuch -> how much

It doesn't know the details of a few less common libc functions.

* skip test_constructor under msan.

* fix the others as well.

* reuse existing related news entry.

* typo fix

Python source code uses on several places ifdef sun or defined(sun) without the underscores, which is not standard compliant and shouldn't be used.

Defines should check for __sun instead. Reference: http://nadeausoftware.com/articles/2012/01/c_c_tip_how_use_compiler_predefined_macros_detect_operating_system#Solaris

https://bugs.python.org/issue35550

Also skip the same tests when using the undefined behavior sanitizer
as they much with the output.

Updates a regex in another test to use multi-line mode so that the ubsan
buildbot should pass again rather than also adding a skip to that one.

HASH_OBJ_CONSTRUCTOR has always been defined as 0 since I created
hashlib in Python 2.5.  Delete all code associated with it.

Add Clang Memory Sanitizer build instrumentation to work around
false positives from the socket and time modules as well as skipping
a couple test_faulthandler tests.

Use crypt_r() when available instead of crypt() in the crypt module.

As a nice side effect: This also avoids a memory sanitizer flake as clang msan doesn't know about crypt's internal libc allocated buffer.

`set_child_watcher()` *sets* the watcher.

* bpo-32492: 2.5x speed up in namedtuple attribute access using C fast path

* Add News entry

* fixup! bpo-32492: 2.5x speed up in namedtuple attribute access using C fast path

* Check for tuple in the __get__ of the new descriptor and don't cache the descriptor itself

* Don't inherit from property. Implement GC methods to handle __doc__

* Add a test for the docstring substitution in descriptors

* Update NEWS entry to reflect time against 3.7 branch

* Simplify implementation with argument clinic, better error messages, only __new__

* Use positional-only parameters for the __new__

* Use PyTuple_GET_SIZE and PyTuple_GET_ITEM to tighter the implementation of tuplegetterdescr_get

* Implement __set__ to make tuplegetter a data descriptor

* Use Py_INCREF now that we inline PyTuple_GetItem

* Apply the valid_index() function, saving one test

* Move Py_None test out of the critical path.

bpo-35602: Make sure the transport is always closed in SelectorEventLoopUnixSockSendfileTests (GH-11338)

There is a race condition in SelectorEventLoopUnixSockSendfileTests that causes the prepare() method return a non connected server protocol, making the cleanup() method skips the correct handling of the transport. This commit makes prepare() always return a connected server protocol that can always be cleaned up correctly.

The problem affects _testWithTimeoutTriggeredSend in test_socket.py.

There is a race condition regarding signal delivery in test_signal_handling_args for
test_asyncio.test_events.KqueueEventLoopTests. The signal can be received at any moment outside the time window provided in the test. The fix is to wait for the signal to be received instead with a bigger timeout.

The attribute is still used in other modules.

This will be needed for other menu items.  Change outwin to call the function instead of updating the menu item directly.

Command line options for the xlc compiler behave differently from gcc and clang,
so skip this test case for now when xlc is the compiler.

Patch by aixtools (Michael Felt)

* Fix test_mktime on AIX by adding code to get mktime to behave the
  same way as it does on other *nix systems
* Fix test_pthread_getcpuclickid in AIX by adjusting the test case
  expectations when running on AIX in 32-bit mode

Patch by Michael Felt.

A few other changes make the code easier to follow.