8076543: Add @modules as needed to the langtools tests
Reviewed-by: jjg, shurailine

8062348: langtools tests should close file manager (group 1)
Reviewed-by: darcy

8005282: Use @library tag with non-relative path for javac tests
Reviewed-by: jjg

7031108: NPE in javac.jvm.ClassReader.findMethod in PackageElement.enclosedElements from AP in incr build
Reviewed-by: darcy, mcimadamore