More JVM tests are needed for sealed classes.

From dholmes as part of sealed classes code review:

On testing:

test/hotspot/jtreg/runtime/modules/SealedModuleTest.java
test/hotspot/jtreg/runtime/sealedClasses/SealedUnnamedModuleTest.java
test/hotspot/jtreg/runtime/sealedClasses/SealedUnnamedModuleIntfTest.java

You don't seem to have coverage of the full test matrix. For the combination of "same module or not" x "same package or not" x "public or not", there should be 8 test cases: 3 failures and 5 successes. Then you also have "listed in permits clause" versus "not listed in permits clause".

Then you have all that for classes and interfaces.