Add a test for jarjar with Java 9 language features.

A genrule generates a clone of Java9LanguageFeaturesTest which uses a
version of Java9LanguageFeatures repackaged by jarjar. This ensures
that jarjar is able to handle a class file which must be at least
v53 and includes bytecode compiled from Java 9 language features.

Test: cts-tradefed run cts-dev -m CtsLibcoreTestCase -t libcore.libcore.internal
Bug: 64761972
Change-Id: I449d903b3cf36a2e8428e8de9097028c57f8c7c5
4 files changed