To test a single jpackage parameter for native packaging we need to create three java sources on each platform. If the parameter is supported on all platforms this results in nine java sources which are 90% copy/paste. This is inefficient. It should be one java test source file per the given functionality to be tested.
Tests that cover shared functionality should be in `test/jdk/tools/jpackage/share` subfolder.
Tests that cover Windows specific functionality should be in `test/jdk/tools/jpackage/windows` subfolder. No `base`, `exe` and `msi` subfolders should be created in `test/jdk/tools/jpackage/windows` subfolder. Similar for Linux and OSX tests.