A number of existing jtreg unit tests require testng (via @run testng) and many more tests are expected to require testng in the future.

The current Netbeans projects in jdk/make/netbeans don't currently provide TestNG symbols so tests referencing them show up as compilation errors.

Adding testng.jar to the purported compilation classpath for jtreg tests will allow easier editing of test sources making use of testng.