bpo-45578: add tests for dis.distb

[sobolevn]

This is the first PR for this issue (I plan to make the second one with dis.findlabels tests).

https://bugs.python.org/issue45578

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @ambv for commit 79b77da 🤖

If you want to schedule another build, you need to add the ":hammer: test-with-buildbots" label again.

[ambv]

Adding buildbot tests as meddling with global state usually causes refleaks or environment change failures.

[sobolevn]

Is it related?

----------------------------------------------------------------------
Ran 1 test in 0.001s
OK
......
1 test failed again:
    test_sqlite3
== Tests result: FAILURE then FAILURE ==
415 tests OK.
10 slowest tests:
- test_signal: 31 min 9 sec
- test_pydoc: 29 min 44 sec
- test_asyncio: 18 min 44 sec
- test_concurrent_futures: 18 min 24 sec
- test_multiprocessing_spawn: 15 min 42 sec
- test_peg_generator: 15 min 23 sec
- test_multiprocessing_forkserver: 9 min 37 sec
- test_multiprocessing_fork: 8 min 25 sec
- test_gdb: 8 min 23 sec
- test_pickle: 5 min 10 sec
1 test failed:
    test_sqlite3
14 tests skipped:
    test_devpoll test_ioctl test_kqueue test_msilib test_smtpnet
    test_ssl test_startfile test_tix test_tk test_ttk_guionly
    test_winconsoleio test_winreg test_winsound test_zipfile64
2 re-run tests:
    test_sqlite3 test_unittest
Total duration: 45 min 44 sec
Tests result: FAILURE then FAILURE
make: *** [Makefile:1357: buildbottest] Error 2
program finished with exit code 2
elapsedTime=2746.496299

[ambv]

This is indeed unrelated, Nikita. It's fixed by GH-29382 already.

[miss-islington]

Thanks @sobolevn for the PR, and @ambv for merging it 🌮🎉.. I'm working now to backport this PR to: 3.9, 3.10.
🐍🍒⛏🤖

[miss-islington]

Sorry, @sobolevn and @ambv, I could not cleanly backport this to 3.10 due to a conflict.
Please backport using cherry_picker on command line.
cherry_picker e346f196819aeb02a8a94205ce3e1536c4c2f105 3.10

[miss-islington]

Sorry @sobolevn and @ambv, I had trouble checking out the 3.9 backport branch.
Please backport using cherry_picker on command line.
cherry_picker e346f196819aeb02a8a94205ce3e1536c4c2f105 3.9

[bedevere-bot]

GH-29385 is a backport of this pull request to the 3.10 branch.

[bedevere-bot]

GH-29386 is a backport of this pull request to the 3.9 branch.