Migrate to PCRE2

[samcday]

I followed this issue for guidance: PCRE2Project/pcre2#51

pcre2 approach seems a bit slower, likely because it's allocating those match_data structs for every check. I tried to allocate it once during init but it seemed to segfault 😅

[samcday]

I based this patch off v21 since master wasn't building cleanly for me. The fix in #61 has been unmerged for a while so I wasn't sure what the state of this project is.

[falconindy]

Just FYI, I think I'd sooner move to RE2 than "upgrade" to PCRE2. I've looked at this before and it's a tire fire.

[loqs]

Just FYI, I think I'd sooner move to RE2 than "upgrade" to PCRE2.

@falconindy Is loqs@1964f49 something similar to what you hand in mind for the move to RE2?

[falconindy]

Just FYI, I think I'd sooner move to RE2 than "upgrade" to PCRE2.

@falconindy Is loqs@1964f49 something similar to what you hand in mind for the move to RE2?

@loqs Looks good! Gave you a code review in the worst way possible. But well, performance of RE2 seems to be junk compared to PCRE despite rsc blog posts suggesting otherwise.

[loqs]

But well, performance of RE2 seems to be junk compared to PCRE despite rsc blog posts suggesting otherwise.

If PCRE2 and RE2 are both out there is std:basic_regex.