Issue 21375:  Fix possible Py_ssizet overflow in heapq.
improve test coverage of filecmp (closes #21357)

Patch by Diana Clarke.
use with blocks to make sure files are closed
Issue #18604: Skip the Tk instantiation test on OS X because it can
cause GUI tests to segfault in Cocoa Tk when run under regrtest -j
(multiple threads running subprocesses).
Issue #21088: Bugfix for curses.window.addch() regression in 3.4.0.
In porting to Argument Clinic, the first two arguments were reversed.
asyncio docs: ProactorEventLoop does not support SSL.
Issue #21366: Document the fact that ``return`` in a ``finally`` clause
overrides a ``return`` in the ``try`` suite.
Add prompts to interactive example.

This makes it match the new example below, and allows Sphinx's
"hide the prompts and output" feature to work.
asyncio: Fix the second half of issue #21447: race in _write_to_self().
#21300: Clean up the docs for the email "policy" arguments.
- Issue #17752: Fix distutils tests when run from the installed location.
- Issue #17752: Fix distutils tests when run from the installed location.
The PyCOND_TIMEDWAIT must use microseconds for the timeout argument
in order to have the same resolution as pthreads condition variables.
At the same time, it must be large enough to accept 31 bits of
milliseconds, which is the maximum timeout value in the windows API.
A PY_LONG_LONG of microseconds fullfills both requirements.
This closes issue #20737
Merging from 3.3: The PyCOND_TIMEDWAIT must use microseconds for the timeout argument
in order to have the same resolution as pthreads condition variables.
At the same time, it must be large enough to accept 31 bits of
milliseconds, which is the maximum timeout value in the windows API.
A PY_LONG_LONG of microseconds fullfills both requirements.
This closes issue #20737
#21300: fix typo
Issue #21396: Fix TextIOWrapper(..., write_through=True) to not force a flush() on the underlying binary stream.

Patch by akira.
Issue #21435: Segfault in gc with cyclic trash
Changed the iteration logic in finalize_garbage() to tolerate objects vanishing
from the list as a side effect of executing a finalizer.
Issue #21157: Touch up imp docs to be more explicit about importlib
alternatives.
Issue #21438: Document what loaders don't require a module name for
load_module().
Issue10752 Be more robust when finding a PERL interpreter to build OpenSSL. Initial patch by Gabi Davar