Change all SVN PHP Linting to PHP7?

Core needs some PHP7-syntax files for the tests folder (latest PHPUnit requires PHP7) to provide a compatibility layer which operates between PHP 5.2 and 7.2 with the default-installed PHPUnit

We’ve previously enabled PHP7 linting for meta.svn and plugins.svn, can we extend that linting to all svn’s?
I don’t expect that a PHP5-specific lint is really required by any of the remaining repo’s. bbPress/BuddyPress/core are going to need PHP7 files at some point, glotpress/w.org/code/etc would benefit from PHP7 syntax too.

ref: https://meta.trac.wordpress.org/ticket/3506 & https://core.trac.wordpress.org/ticket/43218

#prio2