The PCRE lib bundled in the native/iis/pcre directory is a very old 5.0 fork, similar to what Apache httpd used for a long time. It is not hard to update to 8.37, because we only need a few bits from the pcre API which were mostly stable. Our Windows build files can also be adjusted relatively simply to PCRE 8, because we only need the static PCRE lib. Although PCRE supports cmake build, it seems more adequate to not demand downstream to use cmake *just* to build the PCRE needed for the ISAPI redirector. We might go further and switch to PCRE 10, but pushing for the latest 8 IMHO is already a nice improvement making it much easier to stay in sync with future PCRE 8 upstream releases.
Committed in r1700254, will be part of version 1.2.42. I did some build testing on Windows using the iis Makefile.* files and isapi.dsp with MSVC 2010 on Win 7. Needs more testing to check against last minute errors and also some functional runtime testing.