* The primary purpose of pcre2_next_match() is to make it much easier for
PCRE2 clients to iterate over matches, without needing an advanced knowledge
of regular expressions.
* Secondly, we can simplify our own code by merging the three duplicate
implementations of the /g global match behaviour: pcre2demo, pcre2_substitute,
and pcre2test.
* Thirdly, as I look closely at the issue, I can improve the documentation.
* Fourthly, I would like to actually simplify the logic, removing a complex loop
which makes several match attempts, swallows duplicate matches, and more.
We can have identical behaviour with a simple retry using
PCRE2_NOTEMPTY_ATSTART.
I believe this is the correct procedure, based on Philip's documentation.
The libpcre2-posix interface is completely unchanged, but the source code has been updated.
The libpcre2-NN interface has been extended in backwards-compatible ways, with new enum values and API functions, so callers compiled and linked against the old version may use the newer as a drop-in replacement, but callers compiled against the 10.45 headers will fail when used against the old version (if they require any newly-added functions).
The new CI job ensures that `make distcheck` passes.
It also bundles up the tarball and includes in the GitHub artifacts, along with a GitHub-provided attestation that the tarball is derived from the given build steps.
