Issue #22434: Constants in sre_constants are now named constants (enum-like).
Issue #22824:  Updated reprlib output format for sets to use set literals.
Issue #21650: Add an `--sort-keys` option to json.tool CLI.
Merge heads
Issue #22821: Fixed fcntl() with integer argument on 64-bit big-endian
platforms.

--HG--
branch : 3.4
Issue #22821: Fixed fcntl() with integer argument on 64-bit big-endian
platforms.
Issue #12728: Different Unicode characters having the same uppercase but
different lowercase are now matched in case-insensitive regular expressions.

--HG--
branch : 3.4
Issue #12728: Different Unicode characters having the same uppercase but
different lowercase are now matched in case-insensitive regular expressions.
Got rid of the array module dependency in the re module.
The re module could be used during building before array is built.

--HG--
branch : 3.4
Got rid of the array module dependency in the re module.
The re module could be used during building before array is built.
Issue #22578: Added attributes to the re.error class.
Fixed IDLE tests after changing re error messages (issue #22578).
Fixed AttributeError when the regular expression starts from illegal escape.
Issue #22839: Fix Snapshot.statistics() link.

--HG--
branch : 3.4
Issue #22839: Fix Snapshot.statistics() link.