This fixes bugs introduced in [56635] whereby the template or stylesheet path could be memoized incorrectly if `get_template_directory()` or `get_stylesheet_directory()` were called before the theme has been fully initialized.
Props partyfrikadelle, coreyw, kdowns, rebasaurus, meta4, flixos90, mukesh27, joemcgill.
Fixes#59847.
git-svn-id: https://develop.svn.wordpress.org/trunk@57129 602fd350-edb4-49c9-b593-d223f7449a82
