Issue #18076: Introduce imoportlib.util.decode_source().

The helper function makes it easier to implement
imoprtlib.abc.InspectLoader.get_source() by making that function
require just the raw bytes for source code and handling all other
details.
Fix a misnaming of a method and an argument
merge
Merge doc/argument name fix
documentation suggesting something which doesn't exist
Issue #18223: Refactor test_tarfile.

* Use mixins for generating tests for different compression types.
* Make test_tarfile discoverable.
* Use more special tests (i.e. assertEqual, assertIs) instead of assertTrue.
* Add explicit test skips instead of reporting skipped tests as passed.
* Wrap long lines.
* Correct a comment for test_hardlink_extraction1.
* Add support.requires_gzip.

and some other minor enhancements.
Issue #18223: Refactor test_tarfile.

* Use mixins for generating tests for different compression types.
* Make test_tarfile discoverable.
* Use more special tests (i.e. assertEqual, assertIs) instead of assertTrue.
* Add explicit test skips instead of reporting skipped tests as passed.
* Wrap long lines.
* Correct a comment for test_hardlink_extraction1.
* Add support.requires_gzip.
* Replace ImportError by  ModuleNotFoundError.

and some other minor enhancements.
Issue #18207: Fix test_ssl for some versions of OpenSSL that ignore seconds
in ASN1_TIME fields.
Issue #18167: cgi.FieldStorage no more fails to handle multipart/form-data
when \r\n appears at end of 65535 bytes without other newlines.
Issue #18167: cgi.FieldStorage no more fails to handle multipart/form-data
when \r\n appears at end of 65535 bytes without other newlines.
Merge heads
Issue #18147: Add diagnostic functions to ssl.SSLContext().

get_ca_list() lists all loaded CA certificates and cert_store_stats() returns
amount of loaded X.509 certs, X.509 CA certs and CRLs.
merge heads
regrtest.py: Fix typo in the usage of the faulthandler module
(Merge 3.3) regrtest.py: Fix typo in the usage of the faulthandler module
regrtest.py: Fix another typo in the usage of the faulthandler module
(Merge 3.3) regrtest.py: Fix another typo in the usage of the faulthandler module
Issue #18228: Fix locale test of test.regrtest.saved_test_environment

Skip LC_ALL becore getlocale(locale.LC_ALL) always fail, and catch also
ValueError.
Issue #18228: Use locale.setlocale(name, None) instead of
locale.getlocale(name) in test.regrtest.saved_test_environment

locale.getlocale() parses the locale, which is useless for
saved_test_environment.
Issue #18238: Skip test_signal.test_sigwaitinfo_interrupted() on AIX

sigwaitinfo() can be interrupted on Linux (raises InterruptedError), but not on
AIX.