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

8061876: replace java.io.File with java.nio.file.Path (again)
Reviewed-by: ksrini, jlahoda

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

8061723: 8060056 breaks tests on Windows
Reviewed-by: darcy

8060056: replace java.io.File with java.nio.file.Path
Reviewed-by: ksrini, jlahoda

7068451: Regression: javac compiles fixed sources against previous, not current, version of generated sources
Reviewed-by: mcimadamore