Since JDK-8044022 was completed `java -x` output should not contain '-Xincgc' option.

Promoted 9b49:
./java -version
java version "1.9.0-ea"
Java(TM) SE Runtime Environment (build 1.9.0-ea-b49)
Java HotSpot(TM) Server VM (build 1.9.0-ea-b49, mixed mode)

./java -X
    -Xmixed mixed mode execution (default)
    -Xint interpreted mode execution only
    -Xbootclasspath:<directories and zip/jar files separated by :>
                      set search path for bootstrap classes and resources
    -Xbootclasspath/a:<directories and zip/jar files separated by :>
                      append to end of bootstrap class path
    -Xbootclasspath/p:<directories and zip/jar files separated by :>
                      prepend in front of bootstrap class path
    -Xdiag show additional diagnostic messages
    -Xnoclassgc disable class garbage collection
    -Xincgc enable incremental garbage collection
...