Not all modules are listed in Javadoc Requires section

[Zheka Kozlov]

I noticed that for some modules some dependencies are missing in the
Javadoc Requires section.

For example, `java.desktop` depends on `java.prefs`, `java.datatransfer`,
`java.xml` but https://docs.oracle.com/javase/9/docs/api/java.
desktop-summary.html says that it only depends on `java.datatransfer` on
`java.xml`.

Or `java.xml.ws` has 9 dependencies but only 3 transitive dependencies are
listed: https://docs.oracle.com/javase/9/docs/api/java.xml.ws-summary.html

Is this a bug?