pcre2-10.34-RC2 with AArch64 SIMD JIT

I've just pushed pcre2-10.34-RC2 into Fedora 32. Among some boring
featuring like Unicode 12.1.0 and matching in invalid UTF strings, now
the AArch64 JIT compiler uses NEON instructions for better performance.
It's a quite fresh new code and there were some issues with it that
I believe are resolved now.

If you find some strange behavior of PCRE2 on AArch64, let me know.

-- Petr