As mentioned by Adam i the article, try:
There is no "complete" list since you can unpack any PHP extension into the ext/* directory and do a ./buildconf before the ./configure. (Note ./buildconf nowadays might require a later version of autoconf, automake or libtool than Apple provides), but that is a start.
Usually, if there is something missing from the ./configure --help that is documented elsewhere, that feature was removed. (This is not always the case though).
tychay at php dot net