[Checkers] Interaction Between Checkers

[Mahmood Ali]

I was just thinking of how hard it is to have dependancies between  
current factories now, and was wondering if we can do anything about it.

Example:
Any Interned value should be immutable (in the IGJ sense) too.   
However, I cannot easily describe this relation in the current  
framework or checkers.

Currently, one either need to modify IGJ checker to add Interned as  
part of its type qualifiers or create a checker with a special visitor  
that utilizes both annotated type factories.

Proposed idea:
Somehow come up with a "glue" between checkers and be able to lay  
extra relationships bridging the two type qualifiers.

Users can simply specify run (names simplified):
javac -typeprocessor <compine-processor> \
       -checkers IGJChecker:InternedChecker \
       -extra-relationship Interned<Immutable
       ${FILES-TO-COMPILE}

What do you think?

- Mahmood