Fix a misnaming of a method and an argument
merge
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 #18167: cgi.FieldStorage no more fails to handle multipart/form-data
when \r\n appears at end of 65535 bytes without other newlines.
regrtest.py: Fix typo in the usage of the faulthandler module
regrtest.py: Fix another typo in the usage of the faulthandler module
Issue #18238: Skip test_signal.test_sigwaitinfo_interrupted() on AIX

sigwaitinfo() can be interrupted on Linux (raises InterruptedError), but not on
AIX.
ctypes: AIX needs an explicit #include <alloca.h> to get alloca()
test_faulthandler: use _sigsegv() instead of _read_null()

faulthandler._read_null() is not reliable: it does not crash on AIX.