Log Message:
pcre2: update to 10.34.

Version 10.34 21-November-2019
------------------------------

Another release with a few enhancements as well as bugfixes and tidies. The
main new features are:

1. There is now some support for matching in invalid UTF strings.

2. Non-atomic positive lookarounds are implemented in the pcre2_match()
interpreter, but not in JIT.

3. Added two new functions: pcre2_get_match_data_size() and
pcre2_maketables_free().

4. Upgraded to Unicode 12.1.0.