In a message to jdk-dev, it is noted that the reference copy of external-link.svg uses GPL2 but not ClassPath Exception.
While this is not particularly significant, since the file is just a reference copy for the minified version in the stylesheet file, and is not otherwise used in JDK, it is still worth adjusting the license to be consistent with the guidelines for files in the src/ directory.
The file in question is src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/resources/external-link.svg, and contains the following comment:
<!--
A minified version of this file is used as inline SVG icon in the stylesheet.
This file serves only for future editing and is not used by javadoc.
Note that the '#' character in the value of the fill attribute needs to be
URL-encoded when inlined in the CSS file.
-->