bpo-40334: Rename PyConfig.use_peg to _use_peg_parser by vstinner · Pull Request #19670 · python/cpython

* Rename PyConfig.use_peg to _use_peg_parser
* Document PyConfig._use_peg_parser and mark it a deprecated
* Mark -X oldparser option and PYTHONOLDPARSER env var as deprecated
  in the documentation.
* Add use_old_parser() and skip_if_new_parser() to test.support
* Remove sys.flags.use_peg: use_old_parser() uses
  _testinternalcapi.get_configs() instead.
* Enhance test_embed tests

terryjreedy added a commit that referenced this pull request

A tiny sliver of a 3.9 PEG parser patch needed to backport the test added by #20486.

miss-islington pushed a commit to miss-islington/cpython that referenced this pull request

A tiny sliver of a 3.9 PEG parser patch needed to backport the test added by pythonGH-20486.
(cherry picked from commit a5d6aba)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

terryjreedy added a commit that referenced this pull request

A tiny sliver of a 3.9 PEG parser patch needed to backport the test added by GH-20486.
(cherry picked from commit a5d6aba)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>