[Checkers] Arrays and checkers

[Mahmood Ali]

Hi,

> Also, a side issue: I didn't realize that the type validator issued  
> javac errors. If there's a type floating around that is invalid  
> (according to the type validator), is the cause ever the input  
> program and not a problematic checker? If invalid types are only  
> possible via checker bugs, the validator should probably throw some  
> kind of error or exception instead of issuing a compile error.

Due to a lot of the existent confusion, I do think that we should  
rename 'type validator' to a better clearer name.  It checks that all  
the valid uses of a type are essentially subtypes of the element  
declaration type.

Its job is to issue errors when user used '@Mutable String', for  
example. This type is invalid! A similar issue would be if a class as  
annotated with @NonNull, but one used it as @Nullable.  I guess this  
is not quite relevant to Interned.

- Mahmood