Fake a "non-responsive" window width for IE < 9 when folding/unfolding the menu (old IE doesn't support @media), fixes #26458.

Built from https://develop.svn.wordpress.org/trunk@26785


git-svn-id: http://core.svn.wordpress.org/trunk@26672 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/js/common.js

@@ -188,8 +188,8 @@ $(document).ready( function() {
 			// window.innerWidth is affected by zooming on phones
 			respWidth = Math.max( window.innerWidth, document.documentElement.clientWidth );
 		} else {
-			// Exclude IE < 9, it doesn't support @media CSS rules
-			return;
+			// IE < 9 doesn't support @media CSS rules
+			respWidth = 901;
 		}
 
 		if ( respWidth && respWidth < 900 ) {