RFR: 8236272: Improve fidelity between contents of default CDS archive and classes loaded at runtime

[Claes Redestad]

Hi,

when generating the default classlist, doing an extra pass with a
-Xshare:dump between means the final classlist will be more in line
with what will be used at runtime.

Webrev: http://cr.openjdk.java.net/~redestad/8236272/open.00/
Bug:    https://bugs.openjdk.java.net/browse/JDK-8236272

This removes a number of classes from being dumped into the default
archive, effectively reducing size by ~170Kb (~1.5%).

The size reduction might be improved upon further in the future by
making sure that -Xshare:dump can be limited to not dump classes not
listed in the generated classlist, but this requires changes to the
runtime and needs to be thoroughly examined.

Such potential improvements will probably need this build-time fix to be
effective. In the mean-time, this patch provides a small but clear gain.

Thanks!

/Claes