HADOOP-15133. [JDK9] Ignore com.sun.javadoc.* and com.sun.tools.* in animal-sniffer-maven-plugin to compile with Java 9.

hadoop-project/pom.xml

@@ -1569,6 +1569,8 @@
             <ignore>sun.misc.*</ignore>
             <ignore>sun.net.*</ignore>
             <ignore>sun.nio.ch.*</ignore>
+            <ignore>com.sun.javadoc.*</ignore>
+            <ignore>com.sun.tools.*</ignore>
           </ignores>
         </configuration>
       </plugin>