Issue #2388301 by Sam152: Use CSS escape sequence in breadcrumb styles to prevent erroneous delimiter output

core/modules/system/css/system.theme.css

@@ -419,7 +419,7 @@ ul.links a.active {
 }
 /* IE8 does not support :not() and :last-child. */
 .breadcrumb li:before {
-  content: ' » ';
+  content: ' \BB ';
 }
 .breadcrumb li:first-child:before {
   content: none;