package.xml files in core extensions

Hello, I wonder if package.xml files in core extensions still serve their purpose and therefore are needed. As written in message of commit introducing them [1]:

Adding a package.xml to a bundled extension does not only ease the transition to PECL whereever suitable but also allows to build and install an extension as "shared" using the PEAR installer without having to deal with phpize and friends by hand

Is that still a case? Most (if not any) of these files are not up to date and some extensions (e.g. gettext, reflection etc) doesn't have them. By that, I suppose they are not used. Can they be removed? Cheers, Maciej. [1]: https://github.com/php/php-src/commit/eeb172b29f65b9a340638b7096b6dd82399b4562