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

8066843: Messager.printMessage cannot print multiple errors for same source position
Summary: Using a DiagnosticFlag to mark diagnostics that should be always printed even if multiple of them have the same source position.
Reviewed-by: darcy, jjg, mcimadamore

8025246: [doclint] doclint is showing error on anchor already defined when it's not
Reviewed-by: bpatel