Fix anchor not always being put at the right place

Author: GuillaumeGomez

src/librustdoc/html/static/rustdoc.css

@@ -528,6 +528,9 @@ a {
 .anchor.field {
 	left: -5px;
 }
+.small-section-header > .anchor {
+	left: -28px;
+}
 .anchor:before {
 	content: '\2002\00a7\2002';
 }