libpcre2: Default enable JIT support for aarch64

libpcre2: Default enable JIT support for aarch64

JIT support in pcre2 allows for extra performance for regex operations in
applications that support it. As outlined in
https://pcre.org/current/doc/html/pcre2jit.html#SEC2 64-bit ARM is
supported.

I tested this on an GL.Inet MT6000 which is an aarch64 device and to my
knowledge everything works as expected. The primary application I tested
this on was haproxy, which makes use pcre for several operations.

If there are no known downsides or known breakages I suggest to
default-enable this feature for aarch64.

Signed-off-by: Christian Lachner <gladiac@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/20891
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>