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.
Limit the maximum capturing group to 2**30-1 on 64-bit platforms
(it was 2**31-1). No change on 32-bit platforms (2**28-1).
It allows to reduce the size of SRE(match_context):
- On 32 bit platform: 36 bytes, no change. (msvc2022)
- On 64 bit platform: 72 bytes -> 56 bytes. (msvc2022/gcc9.4)
which leads to increasing the depth of backtracking.
* 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`.
Victor Stinner
Serhiy Storchaka
Ma Lin
Brandt Bucher