gh-106320: Remove more private _PyUnicode C API functions (#106382)

[vstinner]

Remove private _PyUnicode codecs C API functions: move them to the internal C API (pycore_unicodeobject.h). No longer export these functions.

• Issue: C API: Remove private C API functions (move them to the internal C API) #106320

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Arch Linux TraceRefs 3.x has failed when building commit d8c5d76.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/484/builds/3599) and take a look at the build logs.
4. Check if the failure is related to this commit (d8c5d76) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/484/builds/3599

Failed tests:

• test__xxsubinterpreters

Summary of the results of the build (if available):

==

Click to see traceback logs

remote: Enumerating objects: 20, done. remote: Counting objects: 5% (1/20) remote: Counting objects: 10% (2/20) remote: Counting objects: 15% (3/20) remote: Counting objects: 20% (4/20) remote: Counting objects: 25% (5/20) remote: Counting objects: 30% (6/20) remote: Counting objects: 35% (7/20) remote: Counting objects: 40% (8/20) remote: Counting objects: 45% (9/20) remote: Counting objects: 50% (10/20) remote: Counting objects: 55% (11/20) remote: Counting objects: 60% (12/20) remote: Counting objects: 65% (13/20) remote: Counting objects: 70% (14/20) remote: Counting objects: 75% (15/20) remote: Counting objects: 80% (16/20) remote: Counting objects: 85% (17/20) remote: Counting objects: 90% (18/20) remote: Counting objects: 95% (19/20) remote: Counting objects: 100% (20/20) remote: Counting objects: 100% (20/20), done. remote: Compressing objects: 11% (1/9) remote: Compressing objects: 22% (2/9) remote: Compressing objects: 33% (3/9) remote: Compressing objects: 44% (4/9) remote: Compressing objects: 55% (5/9) remote: Compressing objects: 66% (6/9) remote: Compressing objects: 77% (7/9) remote: Compressing objects: 88% (8/9) remote: Compressing objects: 100% (9/9) remote: Compressing objects: 100% (9/9), done. remote: Total 20 (delta 11), reused 17 (delta 11), pack-reused 0 
From https://github.com/python/cpython
* branch main -> FETCH_HEAD
Note: switching to 'd8c5d76da2d5c3e8f9c05fcfc59dc1aaaa1fe6e1'.
You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by switching back to a branch.
If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -c with the switch command. Example:
git switch -c <new-branch-name>
Or undo this operation with:
git switch -
Turn off this advice by setting config variable advice.detachedHead to false
HEAD is now at d8c5d76da2 gh-106320: Remove private _PyUnicode codecs C API functions (#106385)
Switched to and reset branch 'main'
Objects/object.c:2197: _Py_ForgetReference: Assertion failed: invalid object chain
Enable tracemalloc to get the memory block allocation traceback
object address : 0x7f6675265c70
object refcount : 0
object type : 0x556b9a5a3660
object type name: tuple
object repr : <refcnt 0 at 0x7f6675265c70>
Fatal Python error: _PyObject_AssertFailed: _PyObject_AssertFailed
Python runtime state: initialized
Thread 0x00007f6676cdd6c0 (most recent call first):
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/test__xxsubinterpreters.py", line 58 in run
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/threading.py", line 989 in run
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/threading.py", line 1052 in _bootstrap_inner
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/threading.py", line 1009 in _bootstrap
Current thread 0x00007f667836a740 (most recent call first):
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/test__xxsubinterpreters.py", line 48 in _wait_for_interp_to_run
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/test__xxsubinterpreters.py", line 66 in _running
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/contextlib.py", line 137 in __enter__
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/test__xxsubinterpreters.py", line 553 in test_still_running
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/unittest/case.py", line 589 in _callTestMethod
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/unittest/case.py", line 634 in run
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/unittest/case.py", line 690 in __call__
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/unittest/suite.py", line 122 in run
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/unittest/suite.py", line 84 in __call__
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/unittest/suite.py", line 122 in run
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/unittest/suite.py", line 84 in __call__
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/unittest/suite.py", line 122 in run
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/unittest/suite.py", line 84 in __call__
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/unittest/runner.py", line 240 in run
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/support/__init__.py", line 1115 in _run_suite
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/support/__init__.py", line 1241 in run_unittest
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/libregrtest/runtest.py", line 294 in _test_module
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/libregrtest/runtest.py", line 330 in _runtest_inner2
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/libregrtest/runtest.py", line 373 in _runtest_inner
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/libregrtest/runtest.py", line 248 in _runtest
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/libregrtest/runtest.py", line 278 in runtest
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/libregrtest/main.py", line 365 in rerun_failed_tests
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/libregrtest/main.py", line 803 in _main
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/libregrtest/main.py", line 758 in main
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/libregrtest/main.py", line 822 in main
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/test/__main__.py", line 2 in <module>
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/runpy.py", line 88 in _run_code
File "/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/Lib/runpy.py", line 198 in _run_module_as_main
Extension modules: _testcapi, _xxsubinterpreters (total: 2)
make: *** [Makefile:2010: buildbottest] Aborted (core dumped)
Cannot open file '/buildbot/buildarea/3.x.pablogsal-arch-x86_64/build/test-results.xml' for upload