In the method jdk.javadoc.internal.doclets.toolkit.taglets.TagletManager#addNewSimpleCustomTag

        Taglet tag = allTaglets.get(tagName);
        if (tag == null || header != null) {
            allTaglets.remove(tagName);
            allTaglets.put(tagName, new SimpleTaglet(tagName, header, locations));
            if (Utils.toLowerCase(locations).indexOf('x') == -1) {
                checkTagName(tagName);
            }
        } else {
            //Move to back
            allTaglets.remove(tagName);
            allTaglets.put(tagName, tag);
        }

Instead of pair LinkedHashMap.get+LinkedHashMap.remove calls, we can use value returned from single allTaglets.remove call.
It's shorter and a bit faster.