This directory originally held the files:

   SolarisLoginModule.java
   SolarisSystem.java
   UnixLoginModule.java
   UnixSystem.java

They were moved to src/share/classes/com/sun/security/auth/module
because they need to be there for Javadoc to include them in 
the JAAS specification.  Moving them derives from the fact that 
the final documentation is built from the platform-specific source 
bundles rather than from the full workspace, so files from all 
platforms need to be in the share directory.  For details, 
see bug 4492476.