[Checkers] Javac Bug Reports

[Mahmood Ali]

Greetings,

I just opened two bug reports with Javac for the following points:

1. Request that either DeclaredType.asElement return TypeElement  
instead of Element, or specify/document the possible return types.

This either eliminates a lot of casts in our code, or helps us  
understand the specification better.

2. Have Element concrete classes (*Symbol) actually override  
Object.equals() to conform to Element interface specification.

We get many assertions failure in Flow because it expect two VarSymbol  
to be equals but not.

-Mahmood