* Add missing type parameters to overrides of ModRef.makeModVisitor
* Add missing type parameters to overrides of ModRef.makeRefVisitor
This also required slightly generalizing the generic type signature of
the ModRef.makeRefVisitor return type. Instead of returning
"RefVisitor<T, ExtendedHeapModel>", we now return "RefVisitor<T, ?
extends ExtendedHeapModel>". We need that extra flexibility because
at least one override of this method returns a RefVisitor whose second
generic type parameter is a subclass of ExtendedHeapModel.
Instead, rely on Java's ability to infer type parameters in many
contexts. This removes 665 Eclipse warnings.
Note: a few of these changes are to files under "test" subdirectories.
Presumably those are files that serve as test inputs rather than being
part of WALA code proper. As far as I can tell, these changes do not
break any WALA tests. But if any of those tests were specifically
intended to exercise WALA on code with non-inferred generic type
parameters, then I really should be leaving those alone.