Revert "Remove IE-specific breadcrumb CSS hack"

This reverts commit 9fda96e197.

scss/_breadcrumb.scss

@@ -21,6 +21,16 @@
     }
   }
 
+  // IE9-11 hack to properly handle hyperlink underlines for breadcrumbs built
+  // without `<ul>`s. The `::before` pseudo-element generates an element
+  // *within* the .breadcrumb-item and thereby inherits the `text-decoration`.
+  //
+  // To trick IE into suppressing the underline, we give the pseudo-element an
+  // underline and then immediately remove it.
+  + .breadcrumb-item:hover::before {
+    text-decoration: underline;
+  }
+  // stylelint-disable-next-line no-duplicate-selectors
   + .breadcrumb-item:hover::before {
     text-decoration: none;
   }