This update for pcre2 fixes the following issues:

- pcre2 10.22:
* The POSIX wrapper function regcomp() did not used to
support back references and subroutine calls if called with the
REG_NOSUB option. It now does.
* A new function, pcre2_code_copy(), is added, to make a copy of a
compiled pattern.
* Support for string callouts is added to pcre2grep.
* Added the PCRE2_NO_JIT option to pcre2_match().
* The pcre2_get_error_message() function now returns with a
negative error code if the error number it is given is unknown.
* Several updates have been made to pcre2test and test scripts
* Fix CVE-2016-3191: workspace overflow for (*ACCEPT) with deeply
nested parentheses (boo#971741)

- Update to new upstream release 10.21
* Improve JIT matching speed of patterns starting with + or *.
* Use memchr() to find the first character in an unanchored match
in 8-bit mode in the interpreter. This gives a significant speed
improvement.
* 10.20 broke the handling of [[:>:]] and [[:<:]] in that
processing them could involve a buffer overflow if the
following character was an opening parenthesis.
* 10.20 also introduced a bug in processing this pattern:
/((?x)(*:0))#(?'/, which was fixed.
* A callout with a string argument containing an opening square
bracket, for example /(?C$[$)(?<]/, was incorrectly processed and
could provoke a buffer overflow.
* A possessively repeated conditional group that could match an empty
string, for example, /(?(R))*+/, was incorrectly compiled.
* The Unicode tables have been updated to Unicode 8.0.0.
* An empty comment (?#) in a pattern was incorrectly processed and
could provoke a buffer overflow.
* Fix infinite recursion in the JIT compiler when certain patterns
/such as (?:|a|){100}x/ are analysed.
* Some patterns with character classes involving [: and \\ were
incorrectly compiled and could cause reading from uninitialized
memory or an incorrect error diagnosis. Examples are:
/[[:\\](?<[::]/ and /[[:\\](?'abc')[a:].
* A missing closing parenthesis for a callout with a string argument
was not being diagnosed, possibly leading to a buffer overflow.
* If (?R was followed by - or + incorrect behaviour happened instead
of a diagnostic.
* Fixed an issue when \p{Any} inside an xclass did not read the current
character.
* About 80 more fixes, which you can read about in the ChangeLog
shipped with the libpcre2-8-0 package.