Issue 46425: Multiple test modules fail to run if invoked directly

While working on a similar issue for `test_typing.py` (https://bugs.python.org/issue46416) I wondered: how many other modules also have this problem?

So, after several hours of local testing, I got several problems:
- Lib/test/test_compileall.py
  Uses relative `.` import that cannot be resolved

- Lib/test/test_distutils.py
  Is missing `import unittest` to run `unittest.main()`

- Lib/test/test_dtrace.py
  Calls undefined `test_main()` instead of  `unittest.main()`

- Lib/test/test_tools/test_freeze.py
  Uses relative `.` import that cannot be resolved

- Lib/test/test_zipfile64.py
  Imports undefined `from test.support import TESTFN`

- Lib/unittest/test/test_program.py
  Uses relative `.` import that cannot be resolved

Probably there are other problems, because I haven't checked:
- Windows tests, because I don't have a Win machine
- `test_importlib`, because it has a lot of failure (I don't know how to fix them yet)
- Multiple other modules with slow tests
- Modules with doctests which assert full `__qualname__` with module names

To keep PRs reviews sane, I will include changes for several modules and split this big task of checking all test modules into several consecutive and rather simple pull requests. 

The first one with the problems described above is on its way!

I suggest your grouping of PRs be by error type -- so have batches of "relative import" fixes and batches of "TESTFN" fixes, etc.

New changeset 1292aa6db5bed889a3c87df443754fcae0177801 by Nikita Sobolev in branch 'main':
bpo-46425: Fix direct invocation of multiple test modules (GH-30666)
https://github.com/python/cpython/commit/1292aa6db5bed889a3c87df443754fcae0177801

Thank you, Ethan. Good idea! Will do from the second PR.
Thanks for merging, Serhiy.

Nikita, thanks for doing this.

Ethan's suggestion has two advantages. 1. It would fix most backport issues.  By containing a mix of changes, PR-30666 cannot be backported as is.  'unittest.main' should always backport unless there is a context conflict.  But 3.9 does not have os.helper and TESTFN is still in test.support in 3.9 and that change cannot backport.  (I did not check 3.10.)

2. It restricts the knowledge needed to review (and be willing to merge).  I could and would review and merge a patch with only unittest.main changes, but not, without checking the docs to learn about new changes, the mixture you posted.

I suggest you write a script to directly run each test.test_xyz file via subprocess and report to stdout.  The test for this issue is a clean report.  If you do so, I will run it on Windows in a fresh build of each of 3.9, 3.10, and 3.11.

Note that there are two possible commands: 'python -m test test_xyz' and 'python -m test.test_xyz'.  They are subtly different.  So I would add an option to do it each way.

With current 3.11, test_importlib runs fine on my Windows, with 1436 tests.

Terry, yes I am using this script to run tests locally:

```bash
#!/usr/bin/env bash

set -e

while read line; do 
  ./python.exe "$line"
done < files.txt
```

And this one to populate `files.txt`:

```bash
find ./Lib -iname 'test*.py' -o -iname '*tests.py' -exec echo {} >> files.txt \;
```

---

There are several other problems that I have to fix manually. For example, module-level `raise unittest.case.SkipTest()`:

```
» ./python.exe Lib/test/test_winreg.py 
Traceback (most recent call last):
  File "/Users/sobolev/Desktop/cpython/Lib/test/support/import_helper.py", line 77, in import_module
    return importlib.import_module(name)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/sobolev/Desktop/cpython/Lib/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1206, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1178, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1142, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'winreg'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/sobolev/Desktop/cpython/Lib/test/test_winreg.py", line 11, in <module>
    import_helper.import_module('winreg', required_on=['win'])
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/sobolev/Desktop/cpython/Lib/contextlib.py", line 155, in __exit__
    self.gen.throw(typ, value, traceback)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/sobolev/Desktop/cpython/Lib/test/support/import_helper.py", line 26, in _ignore_deprecated_imports
    yield
    ^^^^^
  File "/Users/sobolev/Desktop/cpython/Lib/test/support/import_helper.py", line 81, in import_module
    raise unittest.SkipTest(str(msg))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
unittest.case.SkipTest: No module named 'winreg'
```

I am not sure what is the proper solution to this one :thinking:

Probably, I will update my script for more advanced Python-based one and ignore this exception.

In the end, I expect to run this script without any failures. This is going to be a great result! 

---

I will also check that all possible modes `python -m test test_xyz` / `python -m test.test_xyz` / `python Lib/test/test_xyz.py` are supported.

---

Also, thank you for listing concrete problems with my first submission. The second one is bound to a single problem and a single submodule.

Important note, in practice there's also a difference in how one calls some test module:

- python Lib/test/test_contextlib.py
- python ./Lib/test/test_contextlib.py

Example of a test failure because of that: https://github.com/python/cpython/pull/30681

New changeset 8105dd24112509fab2eabfce5352afc41e3a34b6 by Nikita Sobolev in branch '3.9':
[3.9] bpo-46425: Fix direct invocation of multiple test modules (GH-30666) (GH-30700)
https://github.com/python/cpython/commit/8105dd24112509fab2eabfce5352afc41e3a34b6

New changeset a6a088548063226233c08b8d35dde130746fdd10 by Nikita Sobolev in branch '3.10':
[3.10] bpo-46425: Fix direct invocation of multiple test modules (GH-30666) (GH-30699)
https://github.com/python/cpython/commit/a6a088548063226233c08b8d35dde130746fdd10

New changeset 22f73bd9f1fc573d5c998f345b66c29f7ca6614d by Nikita Sobolev in branch 'main':
bpo-46425: Fix direct invocation of `test_contextlib` (GH-30681)
https://github.com/python/cpython/commit/22f73bd9f1fc573d5c998f345b66c29f7ca6614d

New changeset 5a5340044ca98cbe6297668d91bccba04b102923 by Nikita Sobolev in branch 'main':
bpo-46425: fix direct invocation of `asyncio` tests (#30725)
https://github.com/python/cpython/commit/5a5340044ca98cbe6297668d91bccba04b102923

New changeset 3c4a3745b900e748f99e80fc3728b534e857d1ff by Miss Islington (bot) in branch '3.9':
bpo-46425: fix direct invocation of `asyncio` tests (GH-30725)
https://github.com/python/cpython/commit/3c4a3745b900e748f99e80fc3728b534e857d1ff

New changeset 6111d5dee2b24916ff95dba56efc569396a31851 by Miss Islington (bot) in branch '3.10':
bpo-46425: fix direct invocation of `asyncio` tests (GH-30725) (#30782)
https://github.com/python/cpython/commit/6111d5dee2b24916ff95dba56efc569396a31851

New changeset 101a184d49756043a0c39dde6eca08b1891137a2 by Nikita Sobolev in branch 'main':
bpo-46425: fix direct invocation of `test_traceback` (GH-30746)
https://github.com/python/cpython/commit/101a184d49756043a0c39dde6eca08b1891137a2

New changeset 55f4ec460ee6dcffc26180fd982ad89083c9acb1 by Nikita Sobolev in branch 'main':
bpo-46425: use absolute imports in `test_sqlite3` (GH-30676)
https://github.com/python/cpython/commit/55f4ec460ee6dcffc26180fd982ad89083c9acb1

New changeset 57316c52bae5d6420f5067f3891ec328deb97305 by Nikita Sobolev in branch 'main':
bpo-46425: fix direct invocation of `test_importlib` (GH-30682)
https://github.com/python/cpython/commit/57316c52bae5d6420f5067f3891ec328deb97305

New changeset 1f8014c5b4ea7acee069ca453f6fbcad5990ebf0 by Nikita Sobolev in branch 'main':
bpo-46425: fix direct invocation of `test_fileutils` and `test_zoneinfo` (GH-30792)
https://github.com/python/cpython/commit/1f8014c5b4ea7acee069ca453f6fbcad5990ebf0

New changeset d888ff5381594641126065e78dc9210dae4436a4 by Jason R. Coombs in branch 'main':
bpo-46425: Partially revert "bpo-46425: fix direct invocation of `test_importlib` (GH-30682)" (GH-30799)
https://github.com/python/cpython/commit/d888ff5381594641126065e78dc9210dae4436a4