When WordPress is loaded in a function (e.g. unit tests) the variables initialized at the top level aren't globals, but we expect them to be. Explicitly make the version variables global.

Props nbachiyski.
Fixes #23685.


Built from https://develop.svn.wordpress.org/trunk@26008


git-svn-id: http://core.svn.wordpress.org/trunk@25939 1a063a9b-81f0-0310-95a4-ce76da25c4cd