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

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

6987384: -XprintProcessorRoundsInfo message printed with different timing than previous
Reviewed-by: darcy

6988836: A new JavacElements is created for each round of annotation processing
Reviewed-by: darcy