How are the regression tests you have released as part of the buildable OpenJDK code base licensed?
GPL v2 only. There are a small number of files that have no license in the file itself. These files are all licensed under GPL v2 only, as the entire combined work constituting the OpenJDK code base is under GPL v2. These files are mostly data files used in certain tests, for which no provision has been made for comments, and thus which cannot be modified to include the GPL v2 header.