In hotspot/test/runtime/AppCDS, there are a couple of commonly used test library classes: TestCommon.java and JarBuilder.jar. Most of TestCommon and all of JarBuilder should be made open and moved to the root test library.

A new JDK test, jdk/test/com/sun/jdi/cds/CDSJDITest.java, had to copy a number of TestCommon and JarUpdate methods since it could not be co-located in the hotspot directory. These methods include:

TestCommon:
  makeClassList
  executeAndLog
  writeFile
  getOutputFile
  addToClassList
  getTestNamePrefix

JarBuilder:
  buildJar
  createSimpleJar
  createJar

Moving All of JarBuilder and the above parts of TestCommon to the root test library would mean that these methods would no longer need to be copied.

Also, there are some AppCDS JDI tests that were not pushed as part of the fix for JDK-8054386 because there were too many references to TestCommon APIs that are AppCDS specifc (see attached), so they couldn't be copied. These TestCommon APIs would need to be moved to a test library closed repo, which does not yet exist.