Capturing groups that contain recursive backreferences to themselves are no longer automatically atomic.

New option for pcre2_substitute: PCRE2_SUBSTITUTE_LITERAL, PCRE2_SUBSTITUTE_MATCHED, PCRE2_SUBSTITUTE_REPLACEMENT_ONLY.

If PCRE2_UCP is set without PCRE2_UTF, Unicode character properties are used for upper/lower case computations on characters whose code points are greater than 127.

Updated to Unicode 13.0.0.