gh-108851: Fix tomllib recursion tests (#108853)
* Add get_recursion_available() and get_recursion_depth() functions
to the test.support module.
* Change infinite_recursion() default max_depth from 75 to 100.
* Fix test_tomllib recursion tests for WASI buildbots: reduce the
recursion limit and compute the maximum nested array/dict depending
on the current available recursion limit.
* test.pythoninfo logs sys.getrecursionlimit().
* Enhance test_sys tests on sys.getrecursionlimit()
and sys.setrecursionlimit().
Backport notes:
* Set support.infinite_recursion() minimum to 4 frames.
* test_support.test_get_recursion_depth() uses limit-2, apparently
f-string counts for 2 frames in Python 3.11.
* test_sys.test_setrecursionlimit_to_depth() tests depth+2 instead of
depth+1.
(cherry picked from commit 8ff1142578)
This adds a new standard library module, `tomllib`, for parsing TOML.
The implementation is based on Tomli (https://github.com/hukkin/tomli).
## Steps taken (converting `tomli` to `tomllib`)
- Move everything in `tomli:src/tomli` to `Lib/tomllib`. Exclude `py.typed`.
- Remove `__version__ = ...` line from `Lib/tomllib/__init__.py`
- Move everything in `tomli:tests` to `Lib/test/test_tomllib`. Exclude the following test data dirs recursively:
- `tomli:tests/data/invalid/_external/`
- `tomli:tests/data/valid/_external/`
- Create `Lib/test/test_tomllib/__main__.py`:
```python
import unittest
from . import load_tests
unittest.main()
```
- Add the following to `Lib/test/test_tomllib/__init__.py`:
```python
import os
from test.support import load_package_tests
def load_tests(*args):
return load_package_tests(os.path.dirname(__file__), *args)
```
Also change `import tomli as tomllib` to `import tomllib`.
- In `cpython/Lib/tomllib/_parser.py` replace `__fp` with `fp` and `__s` with
`s`. Add the `/` to `load` and `loads` function signatures.
- Run `make regen-stdlib-module-names`
- Create `Doc/library/tomllib.rst` and reference it in `Doc/library/fileformats.rst`
