The org.w3c.dom.xpath package is now exported by the jdk.xml.dom package.
Somehow this copyright file was copied instead of being moved, so now java.xml sources have an empty org.w3c.dom.xpath package that only contains the COPYRIGHT.html file: this file should be removed.

$ diff jaxp/src/java.xml/share/classes/org/w3c/dom/xpath/COPYRIGHT.html jaxp/src/jdk.xml.dom/share/classes/org/w3c/dom/xpath/COPYRIGHT.html

shows that the two files are identical.