The methods of a final class are not marked final, because they may be
shared with other classes. So to know if a method call is final, you
have to check both the method and the type of the object being
dispatched.

Domains come in two syntaxes. The typechecker leaves them as they are.

The modifiers() field on a fields Decl is the one that should be
trusted after resolveClass completes (and not the flags() on the
field itself).

Widening/etc of xxxAssignNodes is handled via the widenSource/castResult
methods. See the comments in AST.h.