add Xpass extension

[remicollet]

https://pecl.php.net/package/xpass

[remicollet]

chicken and egg issue with php/doc-base#209

Build passes locally

$ ./configure.php 
configure.php on PHP 8.3.14

Checking for source directory... /work/GIT/phpdoc/base
Checking for output filename... /work/GIT/phpdoc/base/.manual.xml
Checking whether to include CHM... no
Checking for PHP executable... /usr/bin/php
Checking for language to build... en
Checking whether the language is supported... yes
Checking for partial build... no
Checking whether to enable detailed XML error messages... no
Checking libxml version... 2.12.8
Checking whether to enable detailed error reporting (may segfault)... yes

doc-base: d2dd75b34eda7da0e0fa2e42e1d8ab71f57d9035 (branch issue-xpass)
en:       151476a00a5c8d74d56e0ecd15fb7c9bc718602e (branch issue-xpass)

Generating /work/GIT/phpdoc/base/manual.xml... done
Iterating over extension specific version files... OK
Saving it... OK
Iterating over files for sources info... OK
Generating sources XML... OK
Saving sources.xml file... OK
Modification history file /work/GIT/phpdoc/en/fileModHistory.php not found.
Creating empty modification history file...done.
Creating file-entities.ent... done
Checking for if we should generate a simplified file... no
Checking whether to save an invalid .manual.xml... no
Loading and parsing manual.xml... done.
Running XInclude/XPointer... 0 0 1 done. Performed 1791 XIncludes.
Validating manual.xml... done.

All good. Saved .manual.xml
All you have to do now is run 'phd -d /work/GIT/phpdoc/base/.manual.xml'
If the script hangs here, you can abort with ^C.
         _ _..._ __
        \)`    (` /
         /      `\
        |  d  b   |
        =\  Y    =/--..-="````"-.
          '.=__.-'               `\
             o/                 /\ \
              |                 | \ \   / )
               \    .--""`\    <   \ '-' /
              //   |      ||    \   '---'
         jgs ((,,_/      ((,,___/

 (Run `nice php ./configure.php` next time!)