Add a new Regrtest.run_test() method to ensure that --coverage pass the same
options to the runtest() function.

Move the code to run tests in multiple processes using threading and subprocess
to a new submodule.

Move also slave_runner() (renamed to run_tests_slave()) and
run_test_in_subprocess() (renamed to run_tests_in_subprocess()) there.

with attributes and methods.

The --threshold command line option is now ignored if the gc module is missing.

* Convert main() variables to Regrtest attributes, document some attributes
* Convert accumulate_result() function to a method
* Create setup_python() function and setup_regrtest() method.
* Import gc at top level
* Move resource.setrlimit() and the code to make the module paths absolute into
  the new setup_python() function. So this code is no more executed when the
  module is imported, only when main() is executed. We have a better control on
  when the setup is done.
* Move textwrap import from printlist() to the top level.
* Some other minor cleanup.

now accept the self and the dict keyword arguments.

now accept the self and the dict keyword arguments.

now accept the self and the dict keyword arguments.

argument.

argument.

argument.

unpickler.  Highest 32 bits of 64-bit size for BINUNICODE8 and BINBYTES8
opcodes no longer silently ignored on 32-bit platforms in C implementation.

unpickler.  Highest 32 bits of 64-bit size for BINUNICODE8 and BINBYTES8
opcodes no longer silently ignored on 32-bit platforms in C implementation.

unpickler.  Highest 32 bits of 64-bit size for BINUNICODE8 and BINBYTES8
opcodes no longer silently ignored on 32-bit platforms in C implementation.

and nested format_specs. Patch by Anthon van der Neut.

Replace script_helper.assert_python_ok() with subprocess.run().

It looks like the check for integer overflow doesn't work on x86 OpenBSD 5.8.

Issue #25227: Optimize ASCII and latin1 encoders with the ``surrogateescape``
error handler: the encoders are now up to 3 times as fast.

Initial patch written by Serhiy Storchaka.