Add $wp_query parameter to update_post_thumbnail_cache(). props scribu. see...

Add $wp_query parameter to update_post_thumbnail_cache(). props scribu. see #19949, fixes that ticket for 3.4.



git-svn-id: https://core.svn.wordpress.org/trunk@20646 1a063a9b-81f0-0310-95a4-ce76da25c4cd