gh-110756: Sync regrtest with main branch
Copy files from main to this branch:
* Lib/test/libregrtest/*.py
* Lib/test/__init__.py
* Lib/test/__main__.py
* Lib/test/autotest.py
* Lib/test/pythoninfo.py
* Lib/test/regrtest.py
* Lib/test/test_regrtest.py
Do not modify scripts running tests such as Makefile.pre.in,
.github/workflows/build.yml or Tools/scripts/run_tests.py: do not use
--fast-ci and --slow-ci in this change.
Changes:
* SPLITTESTDIRS: don't include test_inspect.
* Add utils.process_cpu_count() using len(os.sched_getaffinity(0)).
* test_regrtest doesn't use @support.without_optimizer which doesn't
exist in Python 3.12.
* Add support.set_sanitizer_env_var().
* Update test_faulthandler to use support.set_sanitizer_env_var().
Reduce the number of unit tests run for the PGO generation task. This
speeds up the task by a factor of about 15x. Running the full unit test
suite is slow. This change may result in a slightly less optimized build
since not as many code branches will be executed. If you are willing to
wait for the much slower build, the old behavior can be restored using
'./configure [..] PROFILE_TASK="-m test --pgo-extended"'. We make no
guarantees as to which PGO task set produces a faster build. Users who
care should run their own relevant benchmarks as results can depend on
the environment, workload, and compiler tool chain.
