During early VM bootstrap, we create a ModuleEntry for java.base, plus 3 ModuleEntry's for the unnamed modules for the 3 loaders (boot/platform/app).

With the default CDS image, we then create 167 PackageEntry's for the java.base module.

With AppCDS, possibly many more packages will be created in the unnamed module of the app loader.

We should try to archive all the PackageEntry for the java.base module and the 3 main unnamed modules. That way, shared classes of these modules can have a pre-initialized InstanceKlass::_package_entry field, so we can avoid the hashtable lookup at run time. We also save the time for dynamically allocating the PackageEntry's.