Some javac tests have bad/dysfunctional `@clean` tags that are now rejected by newer versions of jtreg (>=7)
They need to be fixed.
tools/javac/6257443/T6257443.java Error. Parse Exception: Bad classname provided for `clean': foo.package-info
tools/javac/jvm/ClassRefDupInConstantPoolTest.java Error. Parse Exception: Bad classname provided for `clean': ClassRefDupInConstantPoolTest$Duplicates.class
tools/javac/warnings/suppress/PackageInfo.java Error. Parse Exception: Bad classname provided for `clean': pack.package-info