Stops style engine from combining CSS selectors by default so that rule order is preserved. Props ramonopoly, rajinsharwar, timdix, costdev, audrasjb, SergeyBiryukov, JeffPaul, mukesh27. Fixes #58811. Built from https://develop.svn.wordpress.org/trunk@56574 git-svn-id: http://core.svn.wordpress.org/trunk@56086 1a063a9b-81f0-0310-95a4-ce76da25c4cd