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

7191449: update copyright year to match last edit in jdk8 langtools repository
Reviewed-by: jjh
Contributed-by: steve.sides@oracle.com

7150784: bad copyright date in file
Reviewed-by: darcy

7086261: javac doesn't report error as expected, it only reports ClientCodeWrapper$DiagnosticSourceUnwrapper
Summary: Missing override for toString() in ClientCodeUnwrapper.DiagnosticSourceUnwrapper
Reviewed-by: jjg