There are a number of AlwaysTrueClosures that only return true. For example:
class AlwaysTrueClosure: public BoolObjectClosure {
public:
  bool do_object_b(oop p) { return true; }
};

The most common reason to create this closure is to be able to pass it to JNIHandles::weak_oops_do, to skip filtering dead oops.

This RFE proposes that we create an overloaded JNIHandles::weak_oops_do function that doesn't require a BoolObjectClosure instance to be passed as an argument. This will remove most ad-hoc AlwaysTrueClosures.