Functions re.sub() and re.subn() and corresponding re.Pattern methods
are now 2-3 times faster for replacement strings containing group references.

Closes #91524

Primarily authored by serhiy-storchaka Serhiy Storchaka
Minor-cleanups-by: Gregory P. Smith [Google] <greg@krypto.org>

…is terminated by a signal or allocation failure (GH-32283) (#93882)

Revert "bpo-23689: re module, fix memory leak when a match is terminated by a signal or memory allocation failure (GH-32283)"

This reverts commit 6e3eee5.

Manual fixups to increase the MAGIC number and to handle conflicts with
a couple of changes that landed after that.

Thanks for reviews by Ma Lin and Serhiy Storchaka.

Revert "bpo-47211: Remove function re.template() and flag re.TEMPLATE (GH-32300)"

This reverts commit b09184b.

…names in RE (GH-91792)

Only sequence of ASCII digits is now accepted as a numerical reference.
The group name in bytes patterns and replacement strings can now only
contain ASCII letters and digits and underscore.

…future (GH-91794)

Only sequence of ASCII digits will be accepted as a numerical reference.
The group name in bytes patterns and replacement strings could only
contain ASCII letters and digits and underscore.

Previously, pickling did not fail, but the result could not be unpickled.

It was initially added to support atomic groups, but that
support was never fully implemented, and CALL was only left
in the compiler, but not interpreter and parser.

ATOMIC_GROUP is now used to support atomic groups.

1. It makes them interned.
2. It allows to add comments to individual opcodes.

…ing in re (GH-91660)

Also test that all extra cases are in BMP.

…H-91702)

In expression (?(group)...) an appropriate re.error is now
raised if the group number refers to not defined group.

Previously it raised RuntimeError: invalid SRE code.

…1665)

re.error is now raised instead of TypeError.

…e version (GH-91580)

* Move the code for generating Modules/_sre/sre_constants.h from
  Lib/re/_constants.py into a separate script
  Tools/scripts/generate_sre_constants.py.
* Add target `regen-sre` in the makefile.
* Make target `regen-all` depending on `regen-sre`.

…H-32333)

They were undocumented and never working.

)

… signal or memory allocation failure (GH-32283)

The sre_* modules are now deprecated.