Don't use the classes we want to test for comparing classes in byte array form in AbstractTest, this can hide bugs (ideally we shouldn't use ClassReader either, but this is harder to do). Also fix 3 bugs found thanks to this refactoring.

The constructor of java.lang.Integer is deprecated in 9 so add some @SuppressWarnings("deprecation") in Opcodes because the code can not be changed without breaking the backward compatibility

Add a comment to ask people to not try to refactor the Integers that are used to represent the states of the locals/stack values to use auto-boxing

- add support in ClassWriter
- add support in optimizer

Fix bug #317576 (deprecate Remapping...Adapter classes, replace them with ...Remapper classes that do not depend on LocalVariablesSorter).