title: Maven 3.5 issue with JDK 9
body: <p>I am using Maven 3.5.0 and JDK 9 build 171. When I tried to compile my project I got an exception:</p>
  
  <pre><code>[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.6.1:compile (default-compile) on project admin: Fatal error compiling: ja-va.lang.NoClassDefFoundError: com/sun/tools/javac/file/BaseFileObject: com.sun.tools.javac.file.BaseFileObject 
  </code></pre>
  
  <p>I added suggested flags to the MAVEN_OPTS but without success:</p>
  
  <pre><code>--add-opens jdk.compiler/com.sun.tools.javac.processing=ALL-UNNAMED --add-opens jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED --add-opens jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED --add-opens jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED --add-opens jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED --add-opens jdk.compiler/com.sun.tools.javac.model=ALL-UNNAMED
  </code></pre>
  
  <p>Any suggestions?</p>