8081472: Add a mode to the tests for class-file attributes which dumps in-memory sources to disk
Reviewed-by: ksrini

8042931: Implement classfile tests for EnclosingMethod attribute.
Reviewed-by: jjg, shurailine, anazarov

8042251: Implement classfile tests for InnerClasses attribute.
Reviewed-by: jjg, anazarov, shurailine