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

7074416: Regression: JSR199: javac doesn't unwrap clientcodewrapper objects
Reviewed-by: mcimadamore

6403465: javac should defer diagnostics until it can be determined they are persistent
Reviewed-by: mcimadamore, darcy