Use gnu-libiconv on alpine only for php iconv extension

[msierks-pcln]

This is likely a controversial change. One issue we have with the Alpine images is the lack of translit support for php iconv extension. This will compile against gnu-libiconv instead of musl's implementation.

Also had to disable compiling the extension as shared object because we're unable to build the extension on PHP 8.0 and greater. Since compiling as shared object was added as a workaround to musl's iconv, I reverted that change across the board.

Open to feedback on this change.

[tianon]

After looking over the details you've provided (and testing way too many combinations locally, which led to lots of cussing about autoconf) and then finding https://www.php.net/manual/en/intro.iconv.php, which includes this gem:

Note that the iconv function on some systems may not work as you expect. In such case, it'd be a good idea to install the » GNU libiconv library. It will most likely end up with more consistent results.

IMO, that's a pretty reasonable "upstream recommendation" for us to just switch unilaterally. I think there's a lot of folks over on #240 that would really enjoy seeing this finally "fixed" in some way. 😄

Just a few minor stylistic nits (that I'm happy to make myself if you'd prefer). 👍

[msierks-pcln]

After looking over the details you've provided (and testing way too many combinations locally, which led to lots of cussing about autoconf) and then finding https://www.php.net/manual/en/intro.iconv.php, which includes this gem:

Note that the iconv function on some systems may not work as you expect. In such case, it'd be a good idea to install the » GNU libiconv library. It will most likely end up with more consistent results.

Interesting, I missed that little tidbit in the docs.

IMO, that's a pretty reasonable "upstream recommendation" for us to just switch unilaterally. I think there's a lot of folks over on #240 that would really enjoy seeing this finally "fixed" in some way. smile

That's great to hear, was a little unsure about this one.

Just a few minor stylistic nits (that I'm happy to make myself if you'd prefer). +1

Thanks, I made all the requested changes which are great. 😄

Also did some further testing, which has all been good so far. Please let me know if there is anything else.