[MSHADE-262] Add jpms goal

**[Robert Scholte](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=rfscholte)** opened **[MSHADE-262](https://issues.apache.org/jira/browse/MSHADE-262?redirect=false)** and commented

With Java 9 we get module descriptors for strong encapsulation and reliable configuration.
When shading we should not merge or ignore these descriptors.
In case of an application we should think of the way spring boot works, i.e. bundle the jars in a jar and provide a new classloader. This is the only way to preserve the strong encapsulation right now.
After a talk with [Phillip Webb](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=pwebb) and [David Blevins](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=dblevins) we came to the conclusion that it should NOT be combined with the current shade goal. First idea was to make a new plugin, but after some rethinking I'd prefer to just make a separate goal for it in this shade-plugin.

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1 votes, 4 watchers

The issue names no files or tests. Start by reading the current shade goal and how it handles Java 9 module descriptors, then investigate the proposed separate jpms goal and its classloader or bundled-JAR requirements. Done means defining and implementing a separate goal without combining it with the existing shade goal while preserving strong encapsulation.

Written by the indexing model from the issue text.