Exclude package-info.class from delegate module to avoid empty packages

[jfallows]

Description

jdeps generates a module-info.java that exports packages even if they have only package-info.class.
jlink complains that a package is empty, even if it includes package-info.class.

So, we need to exclude package-info.class from the delegate module to prevent jdeps from generating a module-info.java that is incompatible with jlink.